COLUMBIA LIBRARIES OFFSITE HEALTH SCIENCES STANDAHD HX641 02254 QP171 .At94 The effect of severe c |f?M/l^U. S. DEPARTMENT OF AGRICULTURE, OFFICE OF EXPERIMENT STATIONS, A. C, TRUE, Direelor. RECAP THE EFFECT SEVERE AND PROLONGED MlISCULAIl WORK 'OOD CONSUMPTION, DIGESTION, AND METABOLISM, AND HL- C- sia:Ei?,3vr_A-isr, i^i-i. id.. HE ME(riANICAE WORK AND EFFICIENCY OF BICYCLERS, ■JR. C- C.A.I?,jPE!:N"TE1?,-, 1VL_ fci. WASHINGTON: GOVERNMENT PRINTING, OFFICE, 1 1) 1 , QP/yf ±L3^ Calumbta 5BnitJer^ttp CoQese of ^tpsitnansi anb ^urgeonsi Hibrarp Digitized by the Internet Archive in 2010 with funding from Open Knowledge Commons (for the Medical Heritage Library project) http://www.archive.org/details/effectofsevereprOOatwa Bulletin No. 98. U. S. DEPARTMENT OF AGRICULTURE, OFFICE OF EXPERIMENT STATIONS, A. C. TRUE, Director. THE EFFECT OF SEVERE AND PROLONGED MUSCULAR WORK ox FOOD CONSUMPTION, DIGESTION, AND METABOLISM, BY .\XD li- C- si3::Bi?,ivi:.A-i\r, ipn. id., AND THE MECHANICAL WORK AND EFFICIENCY OF BICYCLERS, :r. c. c^^e,i='eiq"tei?,, iivE. s. WASHINGTON: GOVERNMENT PRINTING OFFICE, 19 01. 1 LETTER OF TRANSMITTAL. U. S. Department of Agriculture, Office of Experiment Stations, Washingto?}, D. C, June i, 1901. Sir: I have the honor to transmit herewith a report on studies of the effect of severe and prolonged muscnlar work on food consump- tion, digestion, and metabolism. The experiments were made with bicycle racers in a six-da}" contest at the Madison Square Garden, New York City, in December, 1898. The investigation was conducted by W. O. Atwater, special agent in charge of nutrition investigations, and H. C. Sherman, lecturer in chemistry at Columbia University, New York City. In the nutrition investigations conducted by the Department under the auspices of the Office of Experiment Stations considerable attention has been paid to food in connection with mus- cular work. Numerous dietary studies of persons performing vaiying amounts of work under approximately normal conditions have been made. It was believed that the present investigation, in which a large amount of severe work was performed for a considerable period of time, would afford results interesting in themselves and valuable for interpreting the results of other investigations. These studies consti- tute part of the nutrition investigations in charge of this Office and were conducted in accordance with instructions by its Director. In carrying on the work valuable assistance was rendered b}" Messrs. A. P. Bryant, H. M. Burr, P. B. Hawk, E. H. Hodgson, R. D. Milner, and H. E. Wells. The success of the investigation depended in large measure upon the hearty cooperation of the American CVcle Racing Association, under whose auspices the contest was conducted, and of the trainers, Messrs. John West, Joseph Quirk, and Charles McGue, as well as the riders themselves, Messrs. C. W. Miller, F. Albert, and H. Pilkington. Acknowledgment should also be made to Dr. E. E. Smith, through whose kindness the laboratories of Eraser & Co., of which he is director and chief chemist, were available. The supplement on mechanical work and efficiency was contributed by R, C. Carpenter, professor of experimental engineering at Cornell 8 University. Professor Carpenter in recent years has given much atten- tion to the study of the energy expended in driving bicycles and has made many experiments. The data and deductions from these have been embodied, so far as was needful, in his present discussion. The report is respectfully submitted, with the recommendation that it be pu])lished as Bulletin No. 98 of this Office. Respectfully, A. C. True, Director. Hon. James Wilson, Secretary of Agriculture. CONTENTS Page. Food consumption, digestion, and metabolism op bicyclers. By W. 0. Atwater AND H. C. Sherman 7 Introduction ^ 7 Previous investigations on muscular work and the metabolism of nitrogen . 8 Experiments with subjects working specifically for investigation 9 Experiments with professional athletes : . 12 Previous investigations upon muscular work and the metabolism of energy — Efficiency of man as a prime motor 15 Occasion and plan of the present inquiry 18 The subjects of the experiments 19 Surroundings and experimental conditions 21 Daily record of the race 23 Analyses of food materials and feces . 27 Description of samples of food and feces analyzed 28 Dietary studies — Statistics of food consumed 31 Dietary study No. 255, C. W. Miller 32 Dietary study No. 256, F. Albert (previous to the race) 34 Dietary study No. 257, F. Albert (during the race) ... 1 35 Dietary study No. 258, H. Pilkington 38 Food consumption of the bicycle racers compared with that of other athletes 42 Digestion experiments 45 Metabolism of nitrogen 48 Balance of income and outgo of nitrogen 50 Metabolism of energj' 52 Summary 53 Mechanical work and efficiency of bicyclers. By E. C. Carpenter 57 Air resistance 57 Wheel resistance 60 Conclusions and remarks 66 5 ILLUSTRATIONS. Page Ftg. 1. Diagram of track used for six-day racre, Madison Square Garden, New York City, December, 1898 21 2. Curve showing wind resistance for different sjieeds 5£ 3. Cur\'es showing bicycle resistance 62 6 FOOD CONSUMPTION, DIGESTION, METABOLISM, AND MECHAN- ICAL WORK OF BICYCLERS. FOOD CONSUMPTION, DIGESTION, AND METABOLISM OF BICYCLERS. By W. O. Atwater, Ph. P., and H. C. Sherman, Ph. D. ■ INTRODUCTION. One very important phase of the science of nutrition is the relation of food to muscular work. This involves such problems as the source of muscular energy and the economical production of useful work. While naturally the greater part of the experimenting along such lines has been conducted with animals, a considerable number of inves- tigations conducted under the auspices of this Office and the earlier work at the Connecticut Storrs Station have had to do with the sub- ject of muscular work in man. Dietary studies^ have been made with (1) professional men and others performing little muscular work; (2) farmers, mechanics, and others performing a moderate amount of muscular work; (3) .mechanics and others at severe labor; (4) men performing for experimental purposes rather more than their usual amount of work; and (5) college athletes. In some of the experiments made with the respiration calorimeter the effects of muscular work were studied,*^ as was also the case in the digestion and nitrogen metabolism experiments conducted at the Universit}^ of Tennessee.^ In order to judge of the various factors which affect any such sub- ject and to obtain data for comparison it is generally desirable to carry on experiments and make observations under unusual conditions. In December, 1898, a six-day bicycle race was held in Madison Square Garden, New York City, in connection with which it was found possi- ble to study the food consumption of three of the contestants as well as the digestibility of a mixed diet, the metabolism of nitrogen, and 1 For details of these studies see U. S. Dept. Agr., Office of Experiment Stations Buls. 21, 29, 31, 32, 35, 37, 38, -40, 46, 52, 53, 54, 55, 71, 75, and 84, and Connectticut Storrs Sta. Rpts. 1891-1899. HT. S. Dept. Agr., Office of Experiment Stations Buls. 44, 63, and 69. ^U. S. Dept. Agr., Office of Experiment Stations Bui. 89. other problems pertaining to the subject. The race necessitated severe and long' continued muscular exertion. An unusiuil oppt)rtunity was thus offered to study food in its relation to muscular work, and it is believed the results will prove interesting in themselves as well as useful in interpreting the results of other investigations. Before describing the experiments conducted with the bicycle racers a brief summary of the investigations with man upon the effect of severe or long continued muscular work on metabolism which have been conducted by other observers seems necessary. Those here cited have to do with muscular work and its effect on the metabolism of nitrogen and energ3^ PREVIOUS INVESTIGATIONS ON MUSCULAR WORK AND THE METABOLISM OF NITROGEN. Liebig, who divided foods into plastic (nitrogenous) and respiratory (nonnitrogenous) nutrients, maintained that the former were the sources of muscular energy. This view was contested on theoretical grounds by Mayer/ who held that the muscular system was a machine which used for its fuel the carbonaceous and not necessarily the nitrogenous ma- terials brought to it by the blood. Frankland called attention to a paper by John Mayow entitled ' ' De motu musculari et spiritibus animalibus," ^ about a century before Priestly's discovery of oxygen, in which it is stated that muscular power arises from the combustion in the muscles of fat brought by the blood with a gas which the lungs take up in respiration. Lawes and Gilbert in 1854 ^ showed that with animals under uniform conditions as regards exercise the amount of excreted nitrogen de- pends upon the amount ingested, while C. Voit * a few years later demonstrated that under some conditions at least an animal with a uniform ingestion of protein may perform an increased amount of muscular work without increasing the excretion of urea. Lehmann held that the excretion of nitrogen was dependent mainly upon the diet, but that when the latter was uniform the elimination of urea was increased b}'' muscular exercise. Of the many investigations ^ on the effect of muscular work upon ^ Die organiHche Bewegung in ihreiii Zusanniienhaiige niit deni Stoff wechsel. Heil- bronn, 1845, p. 54 et seq. ^ Opera omnia medico-physica. Hagaii coinituin, 1681. ^Chem. Centbl., 1867, p. 770. ■* Unter-Huchungen uVjer den Einfluss des Koclinalzes, des Kaffees und der Muskel- bewegungen auf den St(jffweclisel, 1860; ab«. in Cbeni. Centbl., 1867, p. 774. 'A oondse Hunnnary of 186 experiments with men and 199 with animals in which the effeets of musi-nlar work ui)on the metaljoli.sm of nitrogen was stndied (in a nmn})er oi cases the observations included the metabolism of carbon and energy) may be f(jund in U. S. Dept. Agr., Office of Experiment Stations Bui. 45, pp. 118- 135, 268-283, 355-363, 398, 411. 9 the excretion of nitrogen we cite onl}" those which are in some way similar to that here reported. These may be divided into two classes, (1) experiments in which the subject and his diet were under the con- trol of the experimenter and the work was performed for the purpose of iiivestigation, and (2) experiments in which the diet was not under control, the subjects being professional athletes performing feats of endurance in public, and not primaril}^ for experimental purposes. A brief summary of the more important investigations of this nature which we have found follows. EXPERIMENTS WITH SUBJECTS WORKING SPECIFICALLY FOR INVESTIGATION. Fick and Wislicenus published in 1866 ^ the account of their investi- gation upon the relation of exercise to the elimination of nitrogen. These investigators experimented upon themselves, the work per- formed being the ascent of the Faulhorn, about 6,500 feet. From noon on August 29 until 7 p. m., August 30, they consumed onh^ non- nitrogenous food, the diet being made up essentially of fat, starch, sugar, tea, wine, and beer. • The experiments proper began at 6.15 p. m. on August 29, when the bladder was emptied. The urine formed from this time until 5.10 the following morning was collected and called "night urine." The following 8 hours and 10 minutes were occupied in the ascent and the urine formed during this time was called the "work urine." The urine for five hours and forty minutes after the ascent was collected as "after work urine," and that during the night following was also collected. The two subjects eliminated nearl}^ the same amounts of nitrogen, as shown in the following table: Table 1. — Experiments of Fick and Wislicenus on elimination of nitrogen by the kidneys. Designation. Period covered. Nitroger elimi- nated. Subject A. Subject B. "Niglit urine" Aug. 29, 6.15 p. m., to Aug. 30, 5.10 a. m. (10 hours 55 minutes). Aug. 30, 5.10 a. m. to 1.20 p. m. (8 hours 10 minutes) . Aug. 30, 1.20 p. m. to 7 p. m. (5 hours 40 minutes) Aug. 30, 7 p.m., to Aug. 31, 5.30 a.m. (10 hours 30 minutes). O-rams. 6.92 3.31 2.43 4.82 Grams. 6.68 " Work urine " 3.13 " After-work urine " "Night urine "a 2.42 5 35 o At the beginning of the period in which this urine was collected the subjects consumed a hearty meal, consisting largely of meat. These authors calculated the consumption of protein corresponding to this excretion of nitrogen, and assumed that protein might yield on combustion an amount of energy equal to the sum of the heats of ' Vrtljschr. Naturf. Gesell. Zurich, 10 (1865), p. 317; abs. in Chem. Centbl., 1867, pp. 769-782, * 10 combustion of the c-arbon and hydrog-eii contained in it. From this computation they concluded that the protein consumed could have yielded only from one-half to three-fourths of the energy required to lift the weights of their bodies to the height ascended, while if the work of forward progression and the internal work be taken into account the discrepancy would become much greater. Frankland^ having- determined the actual heats of combustion of protein and urea, calculated the energy availal)le fi-om the consumption of protein by Fick and Wislicenus to be only about two-thirds as much as these investigators had supposed. Thus it was clearly shown that the nitrogen eliminated during and immediately after the work could not account for enough protein to yield the required energy, and, indeed, that the nuiscular work did not cause an increased elimination of nitrogen during or immediately niter the exertion. But it does not follow that such an increase does not normallj' occur. The conditions here were abnormal, in that the subjects were in a state of "nitrogen starvation," and the observa- tions were not continued as long after the exercise as more recent experiments have shown to be necessar}" in order to obtain all of the extra nitrogen eliminated in connection with muscular work. Parkes" published in 1867 the results of a series of experiments made with two soldiers on a uniform mixed diet, with and without muscular work. Each working period was of three days' duration, and was preceded and followed b}^ periods of two or four days during which the subjects followed their usual occupations. We infer that the usual occupations required comparativeh' little muscular exertion. It was found that the work, which consisted in walking on level ground, and did not, b}^ Parkes's computations, exceed 160,000 kilogram- meters per day, caused a small increase in the excretion of nitrogen. This increased excretion, however, continued for some time after the completion of the extra nuiscular work. In 1882 North '^ expei'imeiited upon himself, taking great pains to secui'e uniformity in his diet, and doing- on one day of each expiu'iment a considerable amount of woi'k, walking from 30 to 47 miles and car- rying a load of about 27 pounds. As the weight of the body is not given the amount of work can not be calculated, but it is evidently considerably greater than that done in Parkes's experiments, which North consideri^l not sufficiently severe. The increased elimination of nitrogen with th(^ muscular work was more immediate and more pronounced than in Parkes's experiments. ' 'Phil. Mag., 4. ser., 32 (1867), p. 182. Reprinted in Experiiiicntal Researches in Pure, Applied, and Physical Chemistry. Loiidon, 1877, p. 938. •■'Proc. Roy. 8oc. [London], 1(5 (1867), ]•. 4r). U. S. Dept. Agr., Office of Kxi)eri- ment Stations Bui. 45, pp. 119, 129. •'Pn)c,. Roy. Soe. [London], 36 (1882), p. 14. U. 8. iJept. Agr., Office of Kxperiiuent Stations P.iil. 4r^, pp. I'ZO, 131. 11 It i.s to bo noted, however, that in both of these investigations, in which the diet was the same in the periods of work as in those of rest, the increased metabolism of nitrogenous material, indicated b}" the increased elimination of nitrogen, ina>j have been due to the fact that no increase of fuel ingredients was supplied to meet the increased demand for energy when work was done. Zasietski^ made a number of experiments, each including a rest and a work period, in which milk was the only food allowed, but the quantit}^ was not limited. The work consisted in walking from 9 a. m. to 9 p. m., with short rests. The subjects were mostly peasants or students, and probably had not trained for the exertion. In general no more milk was consumed on the working days than on the da3^s of rest, while the average excretion of nitrogen was 9 per cent greater. Practically all of the recent experimenting with men sustains the view that muscular work normally results in an increased excretion of nitrogen when the work is at all severe and there is not a correspond- ing increase in the fuel ingredients (fats or carbohydrates) of the diet. It also implies that the increased output of nitrogen continues after the work stops, so that if the experiment continues l3ut one day the larger part of the increase may be found on the succeeding day. Among these investigations maj^ be mentioned those of Oppenheim,^ North, ^ Burkalov,* Argutinski,"^ Zuntz," Krummacher,^ Pfliiger,^^ Paton,^ and Punine.^" Hirschfeld" found no change in the nitrogen excretion after exercise, but the amount of exercise taken was relatively small and the fuel value of the diet was high (3,700 to 3,800 calories). All of the investigations above mentioned differ from those reported herewith in that the subjects were not professional athletes and did not perform an amount of work at all approximating to that done in the cases here reported. The same is true, to some extent, of the recent experiments of Dunlop, Paton, Stockman, and Maccadam,^' but as the amount of work performed in these was quite large, and as one 'Vrach, 6 (1887), p. 866. U. S. Dept. Agr., Office of Experiment Stations Bui. 45, pp. 121, 122, 131. 2 Arch. Physiol. [Pfltiger], 23 (1881), p. 497. »Proc. Royal Soc. [London], 36 (1884), p. 11. ''Vrach, 9 (1888), p. 66. sArch. Physiol. [Pfliiger], 46 (1889-90), p. 552. * Arch. Physiol. [Du Bois-Reymond], 1894, p. 541. It should he noted that Zuntz believes the increased proteid metabolism to occur only when the exercise is sufficiently severe to cause labored breathing. 'Arch. Physiol. [Pfliiger], 47 (1890), p. 451; Ztschr. Biol., 33 (1896), p. 108. 8 Arch. Physiol. [Pfluger], 50 (1891), p. 98. 9 Lab. Reports Royal College Phys. Edin., 3 (1891), p. 241. ^^ Liaug. Diss. St. Petersburg, 1894; abs. in U. S. Dept. Agr., Office of Experiment Stations Bui. 45, pp. 123-126, 134. "Arch. Path. Anat. u. Physiol. [Virchow], 121 (1890), p. 504. 12 Jour. Physiol., 22 (1897), pp. 69-98. 12 of the objects was to study the effect of training, they are of special interest in this connection. A brief account of this investigation follows. Five experiments were made, all with men. In three of these the effect of moderately severe muscular exercise was studied, in one the effect of sweating, and in one the effect of massage. The general arrangement was similar in all cases. The subject was put on a rig- idly fixed diet of his own selection for a period of seven days, the muscular work, sweating, or massage occurring on the fourth day. This gave a sufficiently long fore period to show changes on the experi- ment day and a sufficiently long after period to show later changes. Nitrogen was determined in the food, feces, and urine. In the urine, in addition to total nitrogen, sulphur, phosphorus, and uric acid were determined and in some cases sodium, chlorin, preformed ammonia and "extractive" nitrogen as well. Massage produced no marked change in the metabolism and hence it was inferred by the experimenters that the changes observed to result from severe muscular exercise are not due to the physical effects of an increased lymph flow. The only marked effect of sweat- ing upon the urine is a diminution of water and of sodium chlorid. Independently of sweating or of the condition of training, severe mus- cular exertion increased the excretion of nitrogen and sulphur, the increase of nitrogen being due mainly to increased urea, although some was due to increased creatinin and preformed ammonia. When the subject was in poor training there was also an increase in the excre- tion of uric acid, nitrogenous extractives, and phosphoric acid. These changes in urine were held by these investigators to indicate that excessive muscular work causes an increased katabolism of pro- tein, this being simply "muscle proteid" if the subject is in good training, while if the subject is in poor training "this consumption of muscle proteid is accompanied by the consumption of the proteid of other tissues which contain nucleo-proteids as shown by the increased excretion of uric acid, extractive nitrogen, and phosphorus. There may be a withdrawal of proteids from other structures to effect repair in muscles, similar to the transference of material seen in starvation, the proteid portion being retained while the nucleo-acid portion is excreted." Of course it must be remembered that in these experiments the subject was not allowed to increase his diet upon the working day or the days following. This may in part account for the occurrence of phenomena similar to those of fasting. EXPERIMENTS WITH PROFESSIONAL ATHLETES. In the following pag(\s are summarized the experiments of the second class, namely, those in which the diet was not under control, 18 the subjects being professional athletes performing* feats of endurance in public and not primarily for experimental purposes. Flint's^ studies with the professional pedestrian Weston, which were conducted in New,york in 1870, are, so far as we know, the first, and in some respects the best, of investigations of this class. For three consecutive five-day periods, during the second of which he walked 317 miles, Weston was continuously under observation. The food, which during the walk consisted chieflj^ of beef extract, oatmeal gruel, and raw eggs, was carefully weighed and the nitrogen therein computed for the most part from Payen's tables, although some analyses were made. Nitrogen was determined in the feces, and urea, uric acid, sul- phuric acid, and phosphoric acid in the urine. The method for determining the uric acid was faulty and gave too low results. Even had this not been the case there would have been an appreciable amount of undetermined nitrogen in the urine. But in spite of the imperfections of the anal34ical work, the investigation has great value, chiefly because of the long fore and after periods. The results are shown in the following table: Table 2. — Flint's observations on daily nitrogen metabolism by Weston. Occupation. Dura- tion of test. Nitrogen. Period. In food. In urine. In feces. Gain ( +) or loss(-). Fore period Comparative rest Days. 5 ' 5 5 Grams. 22.0 13.2 28.6 Grams. 18.7 21.6 22.0 GraTHS. 1.4 1.6 2.2 6i-ams. + 1.9 -10.0 + 4.4 Working period After period Walking 62 miles per day Rest It will be seen that during the five days of comparative rest before the walk Weston consumed food containing (according to Flint's cal- culation) 22 grams of nitrogen per day and eliminated 18.7 grams in the urine and 1.4 grams in the feces, storing 1.9 grams per day in the body. During the walk he consumed only 13.2 grams of nitrogen per day but eliminated in urine and feces 23.2 grams, making a daily loss of 10 grams of nitrogen from the body. During the five days after the race he consumed 28.6 grams of nitrogen per day and elim- inated 24.2 grams, so that 4.4 grams were stored in the body daily. This investigation shows in a striking manner how the body may draw upon its own protein for the performance of muscular work and after- wards replace the material thus used. It should be noted, however, that the amount of food consumed by Weston during his walk was small. The fuel value of the diet and the relation of this to the mechanical work performed are discussed beyond (see pp. 14 and 56). Six years later Pavy^ investigated Weston's metabolism during ' New York Med. Jour., 13 (1870), p. 653. ^Lancet [Lomlon], 1896, I and II passim. 14 three of his professional walks in England. The observations covered (1) a two-day walk without fore or after periods, (2) a three-da}^ walk with fore and after periods of one day each, and (3) a six-day walk with fore and after periods of six days each. The food consisted largeh' of beef tea, eggs, sea moss farina, and jelly; some meat and bread were also taken and some amounts of brandy and champagne were used. An approximate record of the food was kept and its nitro- gen content was calculated without analysis. During the after period of the third experiment the food was not recorded. Urea and uric acid were determined in the urine. The results are briefl}' summarized in the table herewith, the nitrogen in the urine being calculated by the present writers from the amounts of urea and uric acid found. The data are not sufficient to show the nitrogen balance. Taule 3. — Sammanj of Par-ifs observations on nitrogen metubolism by Weston. Period. First experiment Second experiment: Fore period Working period . After period Third experiment: Fore period Working period . After period Occupation. Dura- tion of test. Walking 90 miles per day. Rest Walking 88 miles per day. Rest Comparative rest Walking Rest Days. 2 Nitrogen per day. In food. In urine. Grams. 7.4 3.3.9 4.5.9 41.8 31.0 43. .'5 (?) Grams. 32.8 19.6 34.8 15.2 20.6 33.8 19.7 It is noticeable that on the two days of the first walk, when the food consumed contained only 7.4 grams nitrogen per day, the nitrogen excretion was practically the same as on other walking da3^s. While these experiments are not suificiently complete to be veiy satisfactory, they agree with those of Flint in showing a large excretion of nitro- gen on the walking dajH. In the second and third of these experi ments, however, the food consumed contained so much protein that there appears to have been little if an}^ loss of bod}'^ nitrogen. In ls78 Jones^ collected and anal3^zed the urine passed by the pro- fessional pedestrian Schmehl during four of six consecutive days in which he walked a total of 500 miles. The average daily excretion of nitrogen in the form of urea and uric acid was 25 grams. The amount and composition of the food were not recorded with suflicient accuracy to indicate whether the body gained or lost nitrogen. In 1S84 Weston undertook and finished successful!}^ a walk of 50 miles per day for 100 consecutive days, 8unda,ys excluded. The last 300 miles were walked on a level indoor track and the food consumed and the metabolism of nitrogen were observed by Blyth.^ The food was weighed or measur(id and the nutrients calculated, as Blyth states, 1 New Orleans Med. and Surg. Jour., 5 (l.S77-7,S), i). 856. M^roc;. Roy. .Soc. [London], 37 (1KS4), j.. 4(j. 15 from "anal3^ses in n\y own work on "Food,' supplemented by the mean numbers given in Konig-'s 'Nahrungsmittel,' and in two instances b}^ analj^ses of the actual foods consumed." The urine for each day was collected ancl analyzed. The feces passed on the last five days, Tuesday to Saturday inclusive, were united and assumed to represent the food of the five da3"s — Monday to Frida}^ of the same week. The food on Saturday being somewhat exceptional, Blyth prefers to omit this day from the average, especially as the feces represent only the other five. The average nitrogen for these five days (Monda}- to Frida}") was: In food, 37.2 grams; in urine, 25.5, and in feces, 9.8, leaving 1.9 grams per da}^ apparently stored in the body. In addition to 235.8 grams of protein the average daih^ diet was estimated to fur- nish Q'i.6 grams of fat and 799.9 grams of carbohydrates. This, according to our usual method of calculation, would furnish 4,850 calories of energy per da3^ This experiment differs from smy of the others in that when it was begun the subject had already" been under- going the same severe exercise for a long time — nearly four months. Brj^ant ^ has calculated, from estimates furnished by Miller's trainer, the nutrients consumed by Miller during the six-daj^ bicycle race at New York in 1897, a year before the present experiment. According to this estimate the diet contained on an average 262 grams of protein and 6,100 calories per dsiv. Nothing is known of the nitrogen excre- tion during these da3"s, but there is no reason to suppose that an3" con- siderable part of this large amount of protein was stored in the body. "That in this case the diet was not greatl3^ at variance with the needs of the bod3^ is indicated b3^ the fact that there was but little change in bod3^ weight during the six da3^s." In general all of these observations indicate that well-trained pro- fessional athletes when engaged in severe muscular exertion metabolize relativel3' large amounts of protein, the bod3" tissue being drawn upon unless the protein of the food is very abundant. Of course the amounts of carboh3"drates and fats in the diet will have a most impor- tant influence, a fact which was not f ull3^ appreciated b3^ the earlier investigators. PREVIOUS INVESTIGATIONS UPON MUSCULAR WORK AND THE METABOLISM OF ENERGY— EFFICIENCY OF MAN AS A PRIME MOTOR. Hirn,^ as earl3' as 1856-57, attempted an investigation of the source of muscular energ3^ and the mechanical efiicienc3' of the human organ- ism. For this latter purpose he emplo3^ed a sort of calorimeter to measure the heat given off' from the body. The calorimeter was a 'Diet. andHyg. Gaz., 15 (1899), p. 393. ^ L' Equivalent niecaniqne de la Chaleur, 1858. Rewritten under the title La Ther- modynamique et 1' etude du travail ehez les etres vivants. Paris, 1887. 16 small room or chamber inside of which the subject was placed during the experiment. Within the calorimeter was a treadwheel turned by power from outside. The muscular work was done and measured by treading the wheel, the arrangements being such that the work done by the subject during one revolution of the wheel was estimated to be equivalent to that required to raise his body through a distance equal to the circumference of the wheel. This was "positive " work. There was also a provision for so-called "negative" work, which is not included in the discussion. The total energy metabolized by the body during the experiment was assumed to be represented by the sum of the heat given ojff from the body as measured by the calorimeter and the heat equivalent of the muscular work as determined by the treadwheel. The heat equiva- lent of the work done divided by this sum was taken as the measure of the mechanical efficiency of the subject. The mechanical efficiency was thus measured in percentage of the total energy metabolized in the body. At the beginning of the experiment the subject worked and breathed in the calorimeter chamber until the temperature had become constant, when the remeasurements were commenced. Each experiment lasted from 40 to 60 minutes, according to the abilit}'^ of the subject to sustain the labor without discomfort. Experiments were made upon five subjects — three men, a lymphatic youth of 18, and a strong young woman of the same age. The efficiencies varied from 17 per cent in the case of the ' ' very lymphatic " youth to 25 per cent in the case of a strong laborer 47 years old. These calculations evi- dently make no allowance for the heat given off from the body when in a state of rest. If such allowance were made, the figures for effi- ciency would of course become higher. Naturally the experimental methods used at this time were not very accurate. Hirn himself recognized this fact and wished to repeat his experiments. Chauveau ' has also criticised the work and pointed out the modifications which should have been introduced, and with which he hopes to repeat the work. Nevertheless the investigation is of decided interest as being the first, and for many years the best, of its kind. Blyth,*^ in reporting his observations on Weston, gives estimates of the amount of work performed by the latter, but does not calculate the fuel value of the diet nor discuss the question of mechanical effi- ciency. Zuntz and his associates have given considerable attention to the subject of muscular work and metabolism, experimenting upon differ- ent animals, including man, and with different forms of work. The general method in all cases involved the determination, by means of 1 Arch, rhysiol. N(jnn. et Path., 5. ser., 9 (1897), p. 229. ^Proc. Roy. Soo. [London], 37 (1884), p. 46. 17 the Zuntz respiration apparatus, of the kinds and amounts of material oxidized in the body, and the calculation of the total energy liberated. The external muscular work was either measured directly or calculated from the weig-ht of" the subject, including in some cases the weight of a burden carried, and the horizontal and perpendicular distance walked or climbed. A careful distinction was made between the energy metab- olized in the performance of the ordinary functions of the bodj^, i. e., internal or physiological work, and the extra energy metabolized in connection with the external work. The latter was calculated by taking the total amount of energy metabolized during a period of work and subtracting from it the amount metabolized by the body during a corresponding period of rest. The difference was taken as represent- ing the amount of energy metabolized for the performance of the external work. Dividing the energy of this external muscular work by the energy especiall}^ metabolized for its performance giv^es the percentage mechanical efficiency of the subject. In a comparatively recent summary of the investigations Zuntz^ has stated that about 35 per cent of the extra energy of the food used in connection with the external muscular work is available for that work, practically the same value being obtained for horses and dogs as for men. Kellner and Wolff,^ experimenting with horses by a radically different method, have reached practically the same result. This interesting agreement is the more surprising in view of the conclusion reached by Kronecker and his associates, Schnyder, and others, in studying the relation of muscular work to the production of carbon dioxid, that the amount of the latter produced depends less upon the amount of work performed than upon the intensit}^ of the exertion, and that the efficiency varies greatl}^ with the condition of the subject and his familiarity with the work. Schnyder^ gives an excellent digest of the work of this character as well as that of Zuntz and his followers. Bryant,* using a modification of Carpenter's ® formula for computing the work done in driving a bicycle, and reducing the fuel value of Miller's diet by the amount believed to be necessary to maintain the body at rest, concludes that this rider maintained during six days of almost continuous bicycle racing an efficiency of 36 per cent. Atwater and Rosa*^ have determined the mechanical efficiency of a man not accustomed to severe exercise who worked in this case eight hours a day on an ergometer, which consisted of a stationary bicycle 1 Experiment Station Record, 7 (1895-96), p. 547. ^Landw. Jahrb.,24 (1895), p. 125; Experiment Station Record, 7 (1895-96), p. 611. ^Ztschr. Biol., 33 (1896), pp. 289-319. ^Diet. and Hyg. Gaz., 15 (1899), p. 393. ^L. A. W. Bulletin 27 (1898), pp. 401, 445, 466. "Phys. Rev., 9 (1899), p. 248. 20695— No. 98—01 2 belted to a .small dynamo. The whole was placed in a respiration cal- orimeter,^ ill ^vhich the subject remained for several days. The total amount of heat g-iven off was accuratel}- measured by means of the calorimeter. The work done was determined b}' measuring the current produced b}^ the dynamo. The electrical energy was then transformed into heat and its amount was included in the total heat measured by the calorimeter. In addition to these heat measurements the total income and outgo of nitrogen, carbon, hydrogen, and water were determined. In these particular experiments the average work done was about -10 watts per day, or 109,000 kilogrammeters, equivalent to 256 calories per da}-. Dividing this b}' the total number of calories measured by the calorimeter, 3,726 per day, they obtain an average mechanical efficiency of 7 per cent of the total energy metabolized. But after deducting the average amount of energy metabolized by the same man when at rest, which had been found by several experiments to be about 2,500 calories, the remainder, which was assumed to be the energy metabolized for the performance of the work, is 1,226 calories per da3", and the mechanical efficiency becomes, for these experiments, 21 per cent. OCCASION AND PLAN OF THE PRESENT INCIUIEY. The six- day bicycle race held in the Madison Square Garden in New York in December, 1898, offered an opportunity for observations on the food consumption and metabolism of trained athletes under condi- tions of unusually prolonged as well as severe exertion. It was hoped at the outset that arrangements would be possible for determining the amount of work done and the mechanical efficienc}" of their bodies, considered as prime motors, with some approach to accuracy. Consid- erable material was gathered for such computations and was used by Professor Carpenter in the preparation of the appended report on the mechanical work and efficiency of the riders. Circumstances have not permitted the direct experimenting with a bicycle dynamometer, which was originally planned. It was reasonably certain that the contestants, stimulated by the pro- fessional importance of the race, the value of the prizes offered, and the size and enthusiasm of their audiences, would perform an amount of work far greater than could be expected of a man working alone for purely experimental purposes, and probably greater than was accom- plished by the professional pedestrian observed by Flint, Pavy, and Blyth. It was also believed that the measurements of income and outgo of matter could be made with considerable more accuracy and complete- ness than was attained in the experiments which these investigators reported. On the other hand, it was evident that the observations ^ U. S. Dept. Agr. , Office of Experiment Stations Bui. 63. 19 would have to be made under considerable disadvantages and that many of the conditions would be beyond control, since no attempt was to be made to regulate the diet or movements of the contestants under observation, and they were not to be subjected to any inconvenience or delaj^s on account of the experiments. It could not be expected, therefore, that the results would be capable of as strict interpretation as in the case of ordinary metabolism experiments, nor was it feasible to observe the metabolism of the men before and after the race, as Flint was able to do in the case of Weston in 1870. The general plan adopted involved the determination of (1) the amount and composition of the foods and beverages used and (2) the amount and composition of the urine and feces excreted. Records of the time occupied in rest and in riding, the approximate number of hours of sleep, and the general changes in body weight were also obtained. Thirty-one contestants entered, and twelve finished, the race. The observations were made upon three, one of whom withdrew early in the fourth day, while the others continued until the close of the race, winning the first and fourth places, respectively. The race began a little after midnight on Sunday night and ended a little after 10 p. m. on the following Saturday night, thus continuing one hundred and fortj^-two hours. The observations were continued during the whole time, daj^ and night. A number of chemists connected with the nutri- tion investigations in progress at Middletown shared with the writers in the observations made on the race track, there being usually three observers present at a time. The labor of making the observations was exacting and practically continuous, as the contestants spent nearly the whole of the time — often twenty-two to twenty-three hours of each da}^ — on the track. The samples were prepared for analysis in a neighboring laboratory. The analyses were made at Middletown, Conn. , in the chemical labora- tory of Weslej^an University. THE SUBJECTS OF THE EXPERIMENTS. All of the subjects had been trained for the race, and two of them were experienced in contests of this sort. Although natives of other countries, all had lived for a number of years in the United States and were in the hands of American trainers, so that there is no reason to doubt that in dietary and most other habits they fairly represent American professional athletes. There are many reasons for believing that in this race Miller was the best representative of the well-trained, well-managed athlete. In the descriptions which follow the data regarding Miller and Pilkington were furnished for the most part by Mr. West, their trainer, while the description of Albert is based mainly on data supplied by himself. 20 C. W. Miller. — Age, 24; height (without shoes), 5 feet 5 inches; weight in ordinary clothing when not in special training, about 172 pounds; in riding costume at the beginning of the race, 15T pounds 12 ounces; at the same time stripped, 153 pounds l-l ounces; waist meas- ure, 34 inches; chest measure, 38 inches; expansion, 37-42 inches. Although a native of Germany, he had lived for six years in Chicago, where, previous to taking up athletics, he was engaged in business. For four years he had devoted himself mainly, and for over two years entirely, to bicycle racing. Mr. Miller always obeyed his trainer and manager without ques- tion and never allowed himself any anxiet}^ regarding business affairs or arrangements of any kind. This circumstance is believed to have been of some advantage to him in his work. According to the state- ments of his trainer, he never uses alcohol or tobacco in any form, and his system of training involved no special deprivations, and there- fore did not wear upon him, his usual habits being such as to necessi- tate no essential change in preparing for a race. Three or four weeks before the present contest he went with his trainer to Cape Girardeau, Mo. , to secure the advantage of warmer weather for his training. Here for two or three weeks he trained by riding 40 or 50 miles per day on an outdoor track. Six days before the race he started for New York, and from then until the race took ver}^ little exercise. During both these periods he lived in hotels and took his meals with his trainer, who limited his diet only by restricting the quantities of pastry and pork consumed. Reaching New York on Friday afternoon before the race, he remained quietly in his hotel nearly all of the intervening time, going out only once to the garden to try the track for a few minutes. Frank Alhert. — Age 28; height (without shoes) 5 feet 8i inches; weight in ordinary clothing when not in special training, about 150 pounds; in riding costume at the beginning of the race, 138 pounds 8 ounces; waist measure, 30 inches; chest measure, 35 inches; expansion, 33-37 inches. Born in Canada of Scotch-Irish parents, he had lived in New York City since boyhood. He early took up athletics and at the time of these experiments had been devoting himself to foot and cj^cle racing for at least ten years and had once held a world's record in the latter. He was his own manager, and thus had manj'^ more arrangements to look after than did Miller. He also attended entirel}^ to his own train- ing, employing a trainer only at the beginning of the race. He states that while temperate in all his habits, he habitually smokes in modera- tion and is not a total abstainer. During the two or three weeks pre- vious to the race he lived in a private family in New York City, not limiting his diet except to avoid veal and fat meats. His exercise consisted in walking several miles every day and riding for a couple of hours, more or less, on a "home trainer," or on a rather small indoor 21 track in the c•it3^ He took pains to secure at least eiLfht hours of sleep every night. During- training he continued to smoke occasionally. He took little exercise on the Friday before the race began and practi- cally none on Saturday and Sunday. From noon of the Thursday to noon of the Saturday before the race it was possible to observe his diet and collect the urine. This covers practically the last day of active training and the first day of comparative rest before the race. Henry Pilkington. — Age 25; height 5 feet 1\ inches; weight in ordi- nary clothing when not in special training, about 150 pounds; in riding- costume at the beginning of the race, 111 pounds 1 ounces; waist meas- ure, 31 inches; chest measure, 36 inches; expansion, 31—39 inches. Born in Ireland, he had lived four years in this countr3^ For five years he had given much time to athletics, but this was his first attempt to ride an endurance race. He had trained with Miller and in a similar man- ner. In disposition he resembled Albert rather than Miller. SURROUNDINGS AND EXPERIMENTAL CONDITIONS. The Madison Square Garden, in which the race here described was held, is practicall)^ a covered inclosure occupying nearly the whole of Fig. 1. — Diagram of track used for six-day race, Madison Square Garden, New York City, December, 1898. a city block. It has seats around the sides for spectators and a great court in the center. Around this court a pine plank track was con- structed for the special purpose of the six-da}^ bicycle race (fig. 1). This track was straight at the sides and semicircular at the ends. The horizontal width was 18 feet, but at all points the outer edge was raised. This elevation of the outer edge was 3 feet at the lowest point (midway of the straight side) and 9i feet at the highest (midwa}^ of the semi- circular end). The "banking" here adopted was said to be somewhat 22 greater than had ])een uyed in previous ,six-day contests, but decidedly less than is usually found on tracks constructed for racing- at high speed. A heavy black line, the ''pole," was drawn around the track 18 inches from the inside edge, as close as it would be practicable to ride at a moderate rate of speed, and served as a sort of guide for the riders. The length of this line was intended to be exactly one-tenth of a mile and was so considered in making up the official record (fig. 1). The contestants, however, did not follow the pole exactly and were apt to ride outside of it, especially when attempting to pass one another. In consequence the distance actually covered was somewhat greater than the records show. Inside the track, along one of its straight sides, was a level space about 6 feet wide. A portion of this space was assigned to each rider. Here his food and drink were brought and handed to him, as described beyond (p. 32). The chemists who made the observations here reported occupied places in this space and had their balances and other appara- tus for weighing and sampling the food on tables here. While engaged in the observations they did not leave this space except to accompany the riders to their quarters. To enable the latter to pass quickly between the track and their quarters, gatewaj^s were provided in the wall on the outer edge of the track at convenient points. Miller and Pilkington were quartered in a small room under one turn of the track and near one of the gateways just described. The room was practically without ventilation, was lighted only by gas, and was used to some extent as a kitchen and as a lounging room. The atmosphere was therefore rather bad, but the temperature of the room was kept at about normal. Most of the other riders, including Albert, were quartered in box stalls in the basement of the building, which had been in use during a horse show but a short time before. These stalls were dark and rather damp and cold. That occupied by Albert was farther from the track and on a lower floor than the room assigned to Miller, and each trip to it necessarily involved a greater loss of time. It is to be remembered, however, that the quarters were but little used. In none of the quarters was there running water, and usually only the hands, face, and feet of the riders were bathed. This is notable in contrast to the frequent bathing usually practiced by amateur athletes or those whose exertions are of short duration. Miller's legs were massaged at frequent intervals, and not infrequently, especially in the last half of the race, his head, neck, and legs were bathi^d with hot water, this being believed to induce wakefulness. As a residt of frequent though not altogether systematic observa- tions, the average temperature on the track was estimated as 58° to &P F. The variations in temperature were sufficient at times to be 23 very noticeable. Sometimes it was cold enough to cause the riders to complain. It was noticeable that even during- the hardest riding none of the racers under observation perspired as freely as would be ex- pected of a man at such severe work. When thej came off the track their clothing was usually damp, but never actually wet. So far as observed, none of the men complained of becoming- warm when riding. The clothing was of such nature that it absorbed and retained con- siderable perspiration, the amount being great enough to prevent the weight of the subjects being ascertained with accuracy when, as was usually necessary, they were weighed dressed. The riders wore, as a rule, two jerseys and two or three pairs of tights or trunks. The glare of the lights in the evenings on the light-colored wooden track and the dust which had gathered before the end of the week affected the eyes of the riders slightl}^ especiall}^ on the last days. Another disagreeable feature, and one of which the riders made the most complaint, was the presence of tobacco smoke, which kept the atmosphere always tainted and often made it very bad. How great was the loss of sleep and how irregular were the habits of even the best managed and most successful of the contestants during- the race will l)e seen from the following record of the two men studied. Owing to unavoidable circumstances it was not possible to obtain the details of Pilkington's record. He was not a prominent contestant and dropped out early in the fourth da}^ of. the race. DAILY RECOED OF THE RACE. Before the beginning- of the race each contestant was subjected to a medical examination, special attention being given to the heart. Physicians were on hand throughout the race for the purpose of watching the riders, examining all who seemed greatly exhausted and stopping any whom they saw lit. Some of these ph5^sicians were employed by the racing association, while others were officers of the New York City board of health and had been detailed for this duty. Monday^ Decemher 5. — ^The contestants, thirtj-one in number, were started at 8 minutes 20 seconds after 12 on the morning of December 5. At 12.44 Miller lost one minute by changing wheels. At 3.35 a. m. Albert left the track, feeling unwell, but returned after a rest of 15 minutes. After riding 7 miles he again rested 5 minutes. From the start the effort of all the leading contestants, especialh'- Miller and two others who were not included in the investigation, was to maintain a high speed, in the hope of wearing out their rivals as early as possible and then to hold the advantage thus won.^ Most of ^ Even in the earliest part of the race the spirits of the riders seemed largely influ- enced by their relative positions among the contestants. It is partly for this reason that the daily progress of Miller and Albert is here given in considerable detail. Inasmuch as Pilkington did not complete the race, details of his record are omitted. 24 the time during- the iirst half da}^ Miller set the pace, and at the end of 1'2 hours he was in the lead with a score of 236 miles. At 12.28 p. m. he dismounted and went to his quarters; changed some of his clothing; remained off his wheel for 12 minutes. At about the same time Albert was off' the track for 11 minutes. At 5.10 p. m. he again left the track for 10 minutes. At 5.16 Miller left the track for 11 minutes' rest and rubbing. He appeared none the worse for his riding and was in excellent spirits. He was also off' his bicycle for 1 to 2 minutes at 6.15, 9.30, 9.45, and 10.10 p. m. The last dismount was due to a fall. Albert was off for 16 minutes at about 10 p. m. An hour later he was again off' for 21 minutes, and at 1.26 a. m. on Tues- day he left the track to sleep and was off nearly an hour, sleeping most of the time. Miller had a 20-minute rest about midnight. At the end of the day Miller had ridden 23 hours and 10 minutes and covered 441.8 miles; Albert, 22 hours and 40 minutes, covering 402 miles. Tuesday, Deceiriber 6. — At 2,20 a. m. Miller left the track and was off' 70 minutes, sleeping about an hour. When he returned he rode for 7 hours without dismounting, keeping, as on the ffrst day, usually at the head of the fastest group of riders. At 10.30 Miller went to his room for 45 minutes, most of which was spent in sleep. On returning he rode hard, with onl}' three stops of 10 to 20 minutes each, until after midnight. During this time both of his opponents had been forced to rest, so that when he stopped, shortly, after midnight, he was only 4 miles behind the leader and was 30 miles ahead of the third. Miller's trainer insisted on his sleeping a second time before noon of this day. Later in the day he secured the lead. Throughout the da}^ Albert kept up a steady, strong pace, and bj^ taking little rest succeeded in covering more distance (371 miles) than any other rider. From 2 a. m. until after noon he did not dismount. During the afternoon he made five stops, aggregating about an hour. When he stopped to sleep, at about 11 p. m., he held third place. He was off' from 11.05 p. m. to 12.33 a. m. and had a little over an hour's sleep. The day's score was: Miller, 21 hours 10 minutes, 366.7 miles; Albert, 21 hours 17 minutes, 371.3 miles. Wednesday, Decemher 7. — Miller and ADjert both went on in good spirits and excellent condition. At 2 a m. the former was second and the latter fifth. At 4 a. m. Miller rested half an hour, and then return- ing, rode rapidly and steadily, gaining the lead early in the morning and holding it most of the day. He made occasional stops, the longest Vjeing at 6 y). m., when he was off' for an hour and slept most of the time. During the day he rode 20 hours 11 minutes, covering 334.1 miles. Albert rode all day at a steady pace. Every hour or two he would dismount for 5 to 20 minutes for a little rest and massage, and he usually ate at these times instead of on his wheel. The dust, smoke, 25 and glare had slightly irritated his eyes. He was unwilling to stop for sleep. At midnight (after 72 hours) he held fourth place. He had ridden during the day 20 hours 41 minutes, covering 352.7 miles. Thursday, Decemher 8.—A.i "l.Ti a. m. Miller left the track for 40 minutes, sleeping most of the time. Three hours later he was again off for 48 minutes. Albert, who had heen without sleep for 30 hours, but with a short rest every hour or two, left the track at 5.45 for 2i hours, getting 2 hours of sleep. Returning, he rode on the same plan as the day before, keeping a good pace, usually in the wake of one of the leading racers, sprinting little, and stopping every hour or two for 5 to 15 minutes. He maintained fourth place all day, gradually increasing his lead over the fifth. Miller, from the time of his return at 6.35 a. m. until 5.50 p. m., lost about 1 hour in five stops, and during the time he was on his wheel kept up a pace of about 18 miles an hour. By noon he had regained first place, but lost it again during one of his ^short rests. When he went to his room at 5.50 he was partiall}^ bathed and well rubbed, and then rested about 1 hour. During the evening he tied for first place with his principal competitor, and they sprinted frequently. During the day Miller rode 19 hours 43 minutes, covering 316.5 miles; Albert, 17 hours 13 minutes, covering 285.3 miles, Friday, December 9. — Soon after midnight Miller's chief competitor left the track for some time. Miller gained the lead and then rested for about 50 minutes. Four times before noon he stopped for 15 to 30 minutes for short rests and massage, but when riding he kept up a pace of 17 or 18 miles per hour. Between 12 and 1 the official score shows that he covered 20. 5 miles. He took a 40-minute rest at 2. 30 and again at 8 p.m., with half a dozen short stops at various times during the da3^ By midnight he had a lead of 37 miles. He had ridden 1,786.9 miles in 120 hours, of which he had spent 103.9 hours on his wheel, making the average rate, when riding, 17.2 miles per hour. Out of the total of about 16 hours spent off' his wheel it was estimated that he had slept about 5 hours. The outside estimate of sleep up to this time would be 6 or 6i hours. A little after midnight Albert left the track for 2^ hours. When he returned he rode much as on the previous da}' , stopping sixteen times before 9.45 p. m., when he again rested for nearly 2 hours. His rid- ing was steady and his spirits and appetite good. The score for the day was: Miller, 327.8 miles in 19 hours 37 min- utes; Albert, 229.4 miles in 14 hours 30 minutes. Saturday^ December 10. — Miller stopped at 1.24 a. m. and took \\ hours' sleep. Before 2 p. m. he made six shorter stops. Then he rested an hour, after which he rode 20 minutes, then was off the track \\ hours. During the remaining 6 hours of the race he rode only 86.7 miles, but it was evident that he could easily have ridden much more had he wished. On several occasions he rode a mile in less 26 than 8 iiiinutes, .soinetinies koepinj>' pace with the .short-distance exhi- bition rider.s for several laps. His record for the day was 220.5 miles in 1-i hours 1-4 minutes, and for the six da3^s was 2,007.4 miles in 118 hours 5 minutes. Until 3 p. m. Albert rode on nuich the same plan as on the other days, except that his speed was lower and his rests longer. As a rule, he would ride 8 to 12 miles in iO to 50 minutes and rest the remainder of the hour. After 3 p. m. he rode only 21 miles in all. His record for the day was 181.9 miles in 12 hours 23 minutes, and for the six days was 1,822.6 miles in 108 hours 41 minutes. At the end of the race he walked without difficulty to his lodg-ings, a distance of about a quarter of a mile. While the race ended officially at 10.08, the contestants had practi- cally stopped racing some time before. At no time after noon did any one of the leading riders appear to be trying to pass the one next ahead of him, and late in the afternoon practically all of them were off the track for some time. Sunday, December 11. — Both Miller and Albert were seen near the middle of the day. There was nothing in the appearance of either to indicate that he had been through an unusual experience. Miller gave public exhibitions upon his bic^^cle during the succeed- ing weeks. Both Miller and Albert took part in a twenty-four-hour race in New York the following month and in a six-day race in San^ Francisco two months later. Miller winning the latter and breaking his New York record. The physical strength and endurance manifested by these men is brought out more clearh^ in the following tabular recapitulation: Table 4. — Recapitulation of score of Miller and Albert. Subject. Monday Tuesday Wednesday Thursday , Friday Saturday, till 10 p. iii . Total for six days Average for six days Total for first live days Average for first Ave days Monday Tuesday Wednesday Thursday , Friday Saturday, till 10 p. m . Total for six days Average for sixdays Total for first (i vc days Average for first five days Riding. Hrs. Min. 23 10 21 10 20 11 19 43 19 37 H 14 Rest. Ilrn. Min. 50 2 50 3 49 4 17 4 23 7 46 22 40 21 17 90 41 17 13 14 30 12 23 108 44 IH 7 91 21 19 1(1 Hrs. Min. 1 40 1 35 1 10 1 5 2 30 lis 5 ; 23 55 19 41 I 3 59 103 51 16 9 20 46 3 14 1 20 2 43 3 19 47 9 30 9 37 33 16 5 33 23 39 4 44 Sleen a I^istance ftieep. a covered. . 8 1 20 5 30 1 6 1 30 20 2 3 40 2 9 30 1 35 7 30 1 30 Miles. 441.8 366.7 334.1 316.5 327.8 220.5 2,007.4 334.6 1,786.9 357. 4 402.0 371.3 352. 7 285.3 229.4 181.9 1,822.6 303. S 1,640.7 328.1 . 47. ^ Based on tiieir relative lieats of combustion per gram, 1 gram of alcohol is isody- namic with 1.7 grams of carbohydrates (7.1^-4.2 = 1.7). 29 No. 3000. Butler. — Purchased in a New York City market. Used in dietary study No. 257. No. 3013. Malted milk. — A commercial preparation. Used in dietary study No. 257. No. 3016. Calf's-foot jelly. — A commercial preparation of gelatin sweetened and flavored with wine. It contained 2.44 per cent alcohol assumed as isodynamic with 4.1 per cent carbohydrates.^ Used in dietary study No. 257. No. 2984. White bread. — Homemade. Used in dietary studies Nos. 256 and 257. No. 2985. Graham bread. — This was what is commonly known as graham gems. Used in dietary study No. 257. No. 2986. Biscuit. — These were the sort of wheat bread known as "raised" bis- cuit, i. e., leavened with yeast. They were unusually dry from having been kept for some time in a paper bag at the track. Used in dietary study No. 257. No. 2978. Oatmeal, boiled.. — Prepared in the usual manner. Used in dietary study No. 256. No. 2988. Oatmeal, boiled. — Prepared in the usual manner. Used in dietary study No. 257. No. 2994. Oatmeal, boiled. — Prepared in the usual manner. Used in dietary studies Nos. 255 and 258. No. 2981. Rice, boiled. — Preparedin the usual manner. Usedin dietarystudy No. 257. No. 2993. Rice, boiled. — Prepared in the usual manner. Used in dietary studies Nos. 255 and 258. No. 2989. Cake. — Sugar cakes purchased from a local bakery. Used in dietary study No. 255. No. 2990. Custard pie. — Purchased from a local bakery. Used in dietary study No. 255. No. 2991. Charlotte russe. — Purchased from a local bakery. Used in dietary study No. 255! No. 2975. Rice pudding. — Homemade. Used in dietary study No. 256. No. 2992. Rice pudding. — Used in dietary study No. 255. No. 2980. Tapioca pudding. — Homemade. Used in dietary study No. 257. No. 2977. Mashed potatoes. — Boiled and mashed with the addition of a little butter and milk. Used in dietary study No. 256. No. 2987. Slewed prunes. — From a jar of stewed dried prunes prepared in a pri- vate family and brought to the track. The sample represents total edible portion including liquor. Used in dietary study No. 257. No. 3017. Oinger cde. — One of the commercial brands commonly sold in New York City. A duplicate sample was purchased for analysis. No alcohol was found. Used in dietary study No. 257. No. 3018. Cocoa urine. — A commercial preparation commonly sold under this name. A duplicate sample was purchased for analysis. It contained 17.36 per cent alcohol assumed as isodynamic with 29.5 per cent carbohydrates.^ Used in dietary study No. 257. N'o. 3010. Feces from Miller. — Representing food eaten during the six days of the race. ^ No. 3011. Feces from Albert. — Representing food eaten during the six days of the race. No. 3012. Feces from Pilkington. — Assumed to represent food consumed during first three days of the race. ^ Based on their relative heats of combustion per gram, 1 gram of alcohol is isody- namic with 1.7 grams of carbohydrates (7.1h-4.2=1.7). 30 Table 5. -Percentage cumpositiun of food materlah aiulfeces analyzed these studies. runnectioH vrilh Labo- ra- tory num- Ref- er- enee num- ber, ber. 2979 2983 2982 299-5 2996 3014 3019 3020 2976 2997 2998 2999 3001 3002 3000 3013 3016 2984 2985 2986 2978 2988 2994 2981 2993 2989 2990 2991 2975 2992 2980 2977 2987 3017 3018 3010 3011 3012 Materials. Pro- tein. ANIMAL KOOD. Roast leg of lamb. Beefsteak Chicken broth Mutton broth Beef tea Vigoral Beet-tea tablets . . . Beef juice Soup Milk do .....do Koumiss Matzoon Butter Malted milk Calf's-foot jelly ... VEGETABLE FOOD. White bread 35. 79 Graham bread 26. 24 Biscuit 16. 74 Oatmeal, boiled 81. 62 do 88. 92 do 86. 18 Rice, boiled 77.62 do 88. 45 Cake ! 23. 80 Custard pie ' 56. 60 Charlotte russe 47. 28 Rice pudding 73. 98 do 70.67 Tapioca pudding 81. 05 Per ct. 60.86 57.58 92.74 95.10 94.93 41.81 10.76 90.98 86.75 88.40 87. 65 88.33 90.35 10. 57 •2.46 81.38 Potatoes, mashed Stewed prunes . . . UNCLASSIFIED FOOD. Ginger ale . Cocoa wine Miller Albert Pilkington 74.10 78.05 89.30 72.04 Fat. Per ct. 29. 62 28.69 3.56 1.08 2.51 a 13. 81 a 16. 06 a 6. 13 1.36 3.15 2.86 \ 3.08 3.62 i 3.08 1.12 14.69 5.31 10.65 10.49 8.66 2.94 1.58 1.99 2.85 .69 7.59 5.67 4.81 3.22 3.15 5.00 2.27 .73 Per ct. 6.79 12.91 2.05 3.26 1.69 1.84 .24 1.77 4.66 3.91 3.79 2.58 3.16 86.04 8.70 .59 .58 9.84 1.10 .64 .52 1.80 .06 12. 71 9.88 21.89 2. 52 2.62 5.26 6.42 .38 26.95 42.76 22. 55 27.08 10.19 38.24 Carbo- hy- drates. Ash. 4.74 4.68 4.13 4.70 4.52 2.67 70.25 14.83 51.42 60.75 62.16 13.58 8.54 10.37 17.29 10.55 54.73 26.40 25.29 19.62 22.73 7.93 15.81 20.13 10.58 35.88 18.95 34.82 9.54 Per ct. 1.62 1.27 1.58 .52 .76 16.01 26.74 1.15 .76 .70 .78 .95 .74 2.27 3.90 .19 1.55 1.94 2.80 .86 .32 .94 .44 .25 1.17 1.45 .73 .66 .83 .76 1.40 .71 .06 3.23 27. 02 12. 23 29.67 Heat of combu.s- tion per gram. Calories. 2.308 2.754 .350 .361 .266 c 1.350 C.960 C.350 .410 .790 .686 .721 .625 .571 8. 005 4.302 .900 2. 797 3.182 3.870 .833 .501 .604 .998 .478 3.773 2.306 3.231 1.200 1.390 1.114 1.316 .975 c450 c 1.500 5.070 5.204 6.480 «The proteid nitrogen was determined by Mallet's method (U. S. Dept. Agr., Division of Chemistry Bui.. 54) and multiplied by 6.25. In our hands Mallet's method gave slightly higher and .somewhat mohe concordant resulti for proteid nitrogen than did the bromin method. (See Bui. 54, above.) 6 As these preparations contained some carbohydrates which could not be satisfactorily determined hf direct estimation, they are calculated by difference in the usual way. The result thus obtained is obviously inaccurate, but is comparable to the so-called "carbohydrates" of other analyses. In esti- mating the carbohydrates by difference the total nitrogeneous matter was computed by multiplying the total nitrogen by 6.25. cHeat of combustion estimated from percentage composition by use of the factors proposed by Atwater and Bryant in Connecticut Storrs Sta. Rpt. 1899, p. 104. A few of the food materials consumed were not analyzed. These were such as previous investigations had shown to be of nearly uniform composition or were used in very small amounts. It was assumed that their composition could be calculated with sufficient accuracy from available data. The values used for this purpose are shown in the following table, together with the calculated heats of combustion per gram.^ 'Tlic heats of coiiilmstion were computed )»y use of thefactoreproi^osed by Atwater and Bryant in Connecticut Storrs Sta. Rpt. 1899, p. 104. 31 Table 6. — Assumed percentage compositiou uf foods not analyzed. Ref- er- ence num- ber. Food materials. ANIMAL FOOD. Beef: Steak (all lean) do Lamb: Chop.s Gravy Poultry: Chicken , Fish: Salmon, canned .. Eggs Butter UNCLASSIFIED FOOD. Soup: Tomato, canned. VEGETABLE FOOD. Cereals: Bread , Vienna Bread, graham Cake, wedding (as average of fruit cakes) Crackers, graham Crackers, soda Doughnuts Sugars, starches, and oils: Sugar Licorice drops (as coffee sugar) . Vegetables: Celery, edible portion Lettuce Peas, stewed a Potatoes, plain boiled Tomatoes, raw Tomato pickles, green Fruits: Apples Apples, as purchased Bananas Grapes, Malaga Oranges, edible portion Fears Peaches Refuse. Per ct. 73.50 70.00 47.60 13.70 59.90 63.50 73.70 11.00 34.20 35.70 17.30 5.40 5.90 18.30 94.50 94.70 73.80 75.50 94.00 93.80 84.60 63.30 75.30 77.40 86.90 84.40 88.10 Pro- tein. Per H. 23. 20 21.30 21.70 4.70 27.00 21.80 13.40 1.00 9.40 8.90 6.90 10.00 9.80 6.70 1.10 1.20 6.70 2.50 1.20 1.10 .40 .30 1.30 1.30 .80 .60 .70 Per ct. 2.50 7.90 29.90 81.80 11.50 12.10 10.50 85.00 1.20 1.80 10.90 9.40 9.10 21.00 .10 .30 3.37 .10 .20 .40 .50 .30 .60 1.60 .20 .50 .10 Carbo- hy- drates. 54.10 52.10 64.10 73.80 73.10 53. 10 100. 00 95.00 3.30 2.90 14.57 20.90 4.00 4.00 14. 20 10.80 22.00 19.20 11.60 14.10 10.80 A.sh. Per ct. 1.20 1.10 1.30 .30 1.30 2.60 1.00 3.00 1.10 1.50 1.80 1.40 2.10 .90 1.00 .90 1.50 1.00 .60 .70 .30 .20 .80 .50 .50 .40 .30 Calcula- ted heat of com- bustion per gram. Calories. 1. 550 1.950 4.070 8.040 2.620 2.380 1.770 7.920 2.920 2.870 3.980 4. 550 4.480 4.570 3.960 3.750 .200 .210 1.200 1.010 .260 .260 .630 .470 1.000 .980 .520 .640 .480 a Composition assumed from that of sample analyzed in connection with dietaries of university boat crews. DIETAEY STUDIES— STATISTICS OF FOOD CONSUMED. The statistics of the amounts and composition of the foods used by the several men under observation were gathered, and are reported as far as possible, in accordance with the methods for dietary studies which have been elaborated and followed in the series of studies of food and nutrition to which these experiments belong/ In some cases special methods were necessary on account of conditions under which the observations were made. No regular meals were eaten. The food was taken at such intervals and in such amounts as suited the convenience of the subject and the judgment of his trainer. The food was prepared in part outside the building, in part at the quarters of the several subjects, and in part at their stands, which were in the space beside the track, which is ^U. S. Dept. Agr., Office of Experiment Stations Buls. 21, 29, etc. Storrs Sta. Rpts. 1891-1897. and Connecticut 32 described aboA'e. Especiallj^ during- the earlier days of the race most of the food was administered in a liquid or semiliquid form. When- ever a rider desired food he called to his trainer in passing the stand. The food was then put into a small tin cylinder of known weight, and the whole weighed by the chemist in attendance. A sig- nal was then given to the rider, who diminished his speed so that the cylinder could be handed to him, and caught in his hand as he rode by. He swallowed the food while riding, and returned the cylinder when passing the stand again. The rider and attendants were very careful to avoid spilling any of the food in handling it after it had been weighed. In a few cases, however, there was a slight loss of food in handing the cylinder to the moving rider or receiving it from him. In such cases it was necessary to deduct the amount which appeared to be thus lost. Such accidents were very rare, and can not be regarded as introducing serious errors. When the cylinder was returned it was weighed, and this weight subtracted from that of cylinder and contents to determine the amount actually eaten. The residue in the can was usually quite small, and in cases in which mixtures were fed the composition of this small residue was assumed to be the same as of the original mixture. When fruit was given the edible portion was weighed and handed directly to the rider, who always consumed it completely. The results of the several dietary studies are tabulated beyond. Following each entry of the amount of a food material is a number in parentheses which corresponds with the number given the same food material in Tables 5 and 6, thus indicating the figures used in com- puting the nutrients in the food. For example, the figure 42 in paren- theses after the first food material in Table 7, eggs 43 grams, refers to reference No. 42 in Table 6 and shows the assumed composition of the eggs. The fuel values were calculated as explained beyond, p. 52. The numbers of the dietary studies 255-258 are those used in the series of such studies made in connection with the general nutrition investigations to which these studies belong. DIETARY STUDY NO. 255, C. W. MILLER. This study covered the entire period of the bicycle race — December 5 to 10, inclusive. Each portion of food, excepting the meat extract, the supply of which was weighed daily, was weighed immediately before })eing eaten. Most of the weighings of food were made on a torsion ])alance, with metric beam graduated to 5 grams and sensitive to 1 gram. This balance was mounted on a small table at the side of the track. As alread}^ noted, the foods taken during the greater part of th(; time were mostly liquid or semiliquid, and were eaten as a rule without dismounting. Toward the end of the race, when Miller dis- mounted more frequently and spont more time in his quarters, he ate 33 a considerable part of his food there. This food was weighed on a spring balance, sensitive to one-half ounce, but as the quantities taken at a time on these occasions were relatively large, and the weighing could be done at leisure, the proportional error was probably not much greater than at the track side. The amount and composition of the food consumed each day, and during the whole period, as well as the averages per day, are shown in the following table: Table 7. — Foods and nutrients consumed by C. W. Miller, December 5-10, inclusive. Kinds and amounts of food consumed. Nutrients and fuel value. Date. Protein. Fat. Carbo- hydrates. Fuel value. 1898. Dec. 5 ANIMAL FOOD. Eggs, raw, 43 gms. (4'2); milk, 690 gms. (12) ; koumiss, 7,138 gms. (13) . Total animal food Grams. 285.4 4.4 Ch-ams. 214.9 2.6 Grams. 355. .178.2 Calories. 4,624 773 VEGETABLE FOOD. Boiled rice, 360 gms. (25); sugar, 72 gms. (51); raw apples, edible portion, 480 gms. (59) . Total vege- table food Total food 289.8 217.5 533.2 5,397 ANIMAL FOOD. Vigoral, 127 gms. (6); eggs. 173 gms. (42); milk, 2,779 gms. (12) ; koumiss, 482 gms. (13) . Total ani- mal food Dec. 6 143.8 16.7 138.3 5.2 163.7 282.7 2,547 1,276 VEGETABLE FOOD. Boiled oatmeal, 418 gms. (23); boiled rice, 225 gms. (25); sugar, 92 gms. (51); apples, 300 gms. (59); oranges, 699 gms. (63). Total vegetable food Total food 160.5 143.5 446.4 3,823 ANIMAL FOOD. Vigoral, 311 gms. (6); milk, 4,937 gms. (12). Total Dec. 7 195.1 40.2 - - 192.8 44.1 259.7 467. 9 3,658 2,493 - VEGETABLE FOOD. Bread, Vienna, 35 gms. (45); charlotte russe, 142 gms. (28); boiled oatmeal, 280 gms. (23); boiled rice, 371 gms. (25); rice pudding, 226 gms. (30); sugar, 53 gms. (51) ; apples, 320 gms. (59) ; oranges, 1,683 gms. (63) . Toral vegetable food '. Total food 235.3 236.9 727.6 6 151 ANIMAL FOOD. Beef extract, 43 gms. (6); matzoon, 476 gms. (14); milk, 581 gms. (12) . Total animal food Dec. 8 38.5 35.1 37.8 40.1 43.8 375. 5 689 VEGETABLE FOOD. Charlotte russe, 71 gms. (28) ; rice pudding, 737 gms. (30); apples, edible portion, 798 gms. (59); or- anges, edible portion, 661 gms. (63) . Total vege- 2, 056 Total food 73.6 77.9 419.3 2, 745 34 Table 7. — Foods and nutrients consumed by C W. Miller, Decembe. 5-10, inclusive — Continued. Kinds and amounts of food consumed. Nutrients and fuel value. Date. Protein. Fat. Carbo- hydrates. Fuel value. 1898. Dec. 9 ANIMAL FOOD. Beef extract, 9 gms. (6) ; eggs, edible portion, 94 gms. (42); milk, 823 gms. (12). Total animal food. VEGETABLE FOOD. Charlotte russe, 170 gms. (2»); custard pie, 839 gms. (27); boiled oatmeal, 8(igms. (23); boiled rice, 300 gms. (25) ; canned tomato soup, 113 gms. (44) ; su- gar, 25 gms. (51); apples, edible portion, 870 gms. (59) Total vegetable food Orams. 39.1 65.1 Grams. 41.3 126.5 Grains. 39.5 ^ 459. 8 Calories. 706 3,329 Total food .... 104.2 167.8 499.3 4 035 ANIMAL FOOD. Beef extract, 5 gms. (6); milk, 1,985 gms. (12). To- Dec. 10 61.8 90.1 75.4 164.1 93.6 791.1 1,339 vegetable FOOD. Charlotte russe, 170 gms. (28) ; custard pie, 867 gms. (27); boiled rice, 252 gms. (25) ; rice pudding, 170 gms. (30): sugar,19gms. (51); sugar cakes, .57 gms. (26); wedding cake, 85 gms. (47); apples, 1,296 gms. (59); Malaga grapes, 865 gms. (62). Total vegetable food 0, i38 Total food 151.9 239.5 884. 7 6,477 127.3 41.9 116.7 63.8 159. 2 425.9 2,260 2, 510 Average per day, total food 169.2 180.6 685.1 4,770 In addition to the food, Miller consumed on the different days the following quantities of coffee infusion: December 5, 767 grams; December 6, 1,446 grams; December 7, 693 grams; December 8, 820 grams; December 9, 2,147 grams; and December 10, 798 grams. Numerous analyses in this laboratory have indicated that the quantity of nitrogen in coffee infusion is so minute as to have no appreciable effect upon the nitrogen balance. DIETARY STUDY NO. 256, F. ALBERT (PREVIOUS TO THE i^ACE). This study covered two days shortly before the race. It began with dinner December 1 and closed with breakfast December 3. The meals were taken at Albert's home. There was no special diet. The foods eaten were those prepared for the family. As previously noted, Albert avoided an cx(-ess of fats and sweets. The food served him at each meal was weighed on a spring balance similar to that used in dietary study No. 2.57. Due account was taken of uneaten residues. The details of the dietary study are shown in the following table: 35 Table 8. — Foods mid nutrients cotisunied by Frank Albert, December 1-3. Kinds and amounts of food consumed. Nutrients and fuel value. Date. Protein. Fat. Carbo- hydrates. Fuel value. 1898. Dec. 1-2 ANIMAL FOOD. Sirloin steak, lean, 142 gms. (36) ; roast leg of lamb, 170 gms. (1) ; gravy from lamb, 14 gms. (39) ; eggs, 170 gms. (42) ; butter, 71 gms. (43) ; milk, 964 gms. (10). Total animal food Grams. 137.9 56.6 Orams. 149.6 29.5 Grams. 4.5.1 335. 7 Calories. 2 141 VEGETABLE FOOD. White bread, 198 gms. (18); graham bread, 28 gms. (46); boiled oatmeal, 397 gms; (21); rice pudding, 213 gms. (29); sugar, 28 gms. (51); lettuce, 85 gms. (54); stewed peas, 85 gms. (55); prepared mashed potatoes, 213 gms. (32); tomato pickles, green,. 57 gms. (58); apples, as purchased, 99 gms. (60); ba- nanas, edible portion, 85 gmg. (61); canned peaches, 142 gms. (65) . Total vegetable food Total food 1,883 194. 6 179.1 380.8 4,024 ANIMAL FOOD. Round steak, lean, 99 gms. (37) ; sirloin steak, lean, 99 gms. (36); canned salmon, 57 gms. (41); eggs, 114 gms. (42) ; butter, 78 gms. (43) ; milk, 255 gms. (10). Total animal food Dec. 2-3 80.5 62.4 107.4 19.9 11.9 356.3 1,377 VEGETABLE FOOD. Bread, 283 gms. (18); boiled oatmeal, 354 gms. (21); rice pudding, 184 gms. (29); sugar, 57 gms. (51); stewed peas, 113 gms. (55); plain boiled potatoes, 100 gms. (56) ; tomato pickles, 71 gms. (58); vege- table soup, 298 gms. (9); canned peaches, 142 gms. (65). Total vegetable food 1 902 Total food 142.9 127.3 368. 2 3 279 Average per day, animal food. 109.2 59.5 128.5 24.7 28.5 346.0 1, 7.59 1 892 Average per day, vegetable food Arerage per day, total food 168.7 163.2 374.5 3,651 DIETARY STUDY NO. 257, F. ALBERT (DURING THE RACE). This study covered the six days of the race (December 6 to 10, inclusive). Some of the subject's food was brought from his home; the rest was prepared at his stand by the track side. The conditions attending the dietary study were less favorable for accuracy than were those in the study made with Miller. The space available for the work was very small, the table was in a crowded corner where it was frequently shaken, and the weighings had to be made very quickly. For these reasons it did not seem practicable to make the weighings on anything more delicate than a spring balance. A very accurate spring balance was obtained which was usually read to one-fourth ounce, but when time allowed could be made to indicate one-eighth ounce. At first each lot of food was weighed, but as the amount taken at a time was usually quite small it was soon seen that there was a possibility of considerable error in the weighings. As soon as practicable (on the second day) it was arranged to have most of the articles of food used by the rider kept separate from that of his attendants. The rider's foods were then weighed at the beginning and end of each day, thus 3R greatly roducino- the number of weighings and the probable error. Even aftei this was done, however, the amounts of food eaten were probably less accurately determined than in dietary studies Nos. 255 and 258. During the last half of the race Albert consumed the greater part of his food while resting at his stand beside the track. The details of this dietary study are given in the following table: Table 9. — Foods and nutrients consumed by Frank Albert, December 5-10. Kinds and amounts of food consumed. Nutrients and fuel value. Date. Protein. Fat. Carbo- hydrates. Fuel value. 1898. Dec. 5 ANIMAL FOOD. Beefsteak, lean, 85 gms. (36); beef tea, 440 gms. (5); eggs, 241 gms. (42); butter, 142 gms. (15); milk, Grams. 79.9 68.9 16.7 Grams. 177.8 14.0 7.9 Grams. 21.9 465.2 247. 9" Calories. 2,071 VEGETABLE FOOD. Bread, 3G8 gms. (18); graham bread, 85 gms. (19) graham crackers, 6 gms. (48); boiled oatmeal, ti94 gms. (22); boiled rice, 241 gms. (24); .sugar, 03 gms. (51); celery, 78 gms. (53); apples, 376 2, 320 I'XCLASSIFIED FOOD. Ginger ale, 1,680 gms. (34); calf's-foot jelly, 42 gms. (17); malted milk, 91 gms. (16). Total un- 1*158 Total food 165.5 199.7 735.0 5,549 ANIMAL FOOD. Beefsteak, lean, 28 gms. (36); beef juice, 128 gms. (8); lamb chops, 78 gms. (38); chicken, 42 gms. (40); chicken broth, 170 gms. (3); eggs, 57 gms. (42); butter, 64 gms. (15); milk, 116 gms. (11). Dec. {•> 60.4 37.0 18.1 97.9 9.0 7.1 4.8 431.8 201. 3 1,178 VEGETABLE FOOD. Bread,198gms. (IS); graham crackers, 6 gms. (48); boiled oatmeal, :!17 gms. (22): sugar, 119 gms. (51); licorice drnps, IS gms. (52); celery, 78 gms. (53); raw tomatoes, 220 gms. (57); raw apples, edible portion, 21)9 gms. (59); California grapes, 99 gius. ((12); oranges, edible portion, Kii gms. (63); slewed prunes, 376 gms. (33). Total vege- 2,005 rXCLASSIFIED FOOD. Ginger ale, 1,248 gms. (34); calf's-foot jelly, 99 gms. (17); malted milk, 82 gms. (16). Total un- 978 Total food 115.5 114.0 640.9 4,161 Dec. 7 ANIM.VL FOOD. Beefsteak, loan, 50 gms. (36); beef juice, 14 gms. (8); l)eef-tea tablets, lOgm.s. (7); vigoral,18gms. (6); lambchop.s, M gm.s. (38); chicken, 85 gms. (40); chicken broth, 283 gms. (3); egg.s, 369 gms. (42); butter, 78 gms. (15); milk, 142 gms. (11). 107.0 56. 8 132. 7 13.6 7.5 563.7 1,704 VEGET.\BLE FOOD. White bread, 177 gms. (18); graham gems, 184 gms. (19); boiled oatmeal, 5;V2 gms. (22); sugar 177 gms. (51); celcrv. 78 gms. (53); raw tomatoes, 29 gms. (.57); vegetable .soup, 191 gins. (9); apples, edible portion, 192 gins. (.59); Malaga grapes, l:i8 gms. (62); f)ranges,e(lil)le i)orti()n,326 gms. (63); stewed prunes, 170 gms. (33). Total vegetable food 2,670 37 Table 9. — Foods and nutrients consumed by Frank Albert, December 5-10 — Continued. Kinds and amouuts of food consumed. Nutrients and fuel value. Date. Protein. Fat. Carbo- hydrates. Fuel value. 1898. UNCLASSIFIED FOOD. Grams. Gravis. Grams. Calorics. Dec. 7 Cocoa wine, 170 gms. (35); ginger ale, 2,459 gms. (34); calfs-foot jelly, 213 gms. (17); malted milk, 78 gms. (16). Total vinclassified food Total food 24.2 6.8 407.5 1,833 188.0 153.1 978.7 6,207 ANIMAL FOOD. Dec. 8 Beefsteak, lean, 71 gms. (36); beefsteak, 71 gms. (2); beef juice, 11 gms. (8); beef-tea tablets, 5 gms. (7); vigoral, 27 gms. (0); mutton broth, 539 gms. (4); chicken, 64 gms. (40); chicken broth, 340 gms. (3); eggs, 283 gms. (42); butter, 198 gms. (15); milk, 312 gms. (11). Total animal food VEGETABLE FOOD. 126. 2 255.8 15.3 2, 959 Bread, 170 gms. (18); "raised" biscuits, 43 gms. (20); doughnuts, 49 gms. (50); graham gems, 397 gms. (19); sugar, 142 gms. (51); apples, 390 gms. (59); bananas, 92 gms. (61); Malaga grapes, 99 gms. (62); oranges, edible portion, 64 gms. (63); pears, 283 gms. (64). Total vegetable food 73.0 23.4 665.2 3, 245 UNCLASSIFIED FOOD. Cocoa wine, 198 gms. (35); ginger ale, 1,581 gms. (34); call's-foot jelly, 269 gms. (17); malted milk, ;S6 gms. (16). Total unclassified food Total food 20.5 3.1 303.5 1,357 219.7 282.3 984.0 7,561 ANIMAL FOOD. Dec. 9 Beefsteak, lean, 170 gms. (36); chicken (cooked) capon, 156 gms. (40); chicken broth, 305 gms. (3); eggs, 56 gms. (42); butter, 220 gms. (15); milk 149 gms (11). Total animal food 106.7 229. 5 0.1 2, 597 VEGET.ABLE FOOD. Bread, 553 gms. (18); soda crackers, 28 gms. (49); graham gems, 128 gms. (19); tapioca pudding, 170 gms. (31); sugar, 135 gms. (51); celery, 49 gms. (53); apples, 418 gms. (59); Malaga grapes, 156 gms. (62); oranges, 234 gms. (63); pears, 319 gms. (64); stewed prunes, 319 gms. (33). Total vege- 9:3.8 23.5 758.3 3,712 UNCLASSIFIED FOOD. Cocoa wine, 43 gms. (35); ginger ale, 1,623 gms. (34); calfs-foot jelly, 156 gms. (17); malted milk, 21 gms. (16). Total unclassified food Total food 12.4 1.8 225.0 990 212.9 254.8 989.4 7,299 ANIMAL FOOD. Dec. 10 Beefsteak, 64 gms. (2); lamb chops, 71 gms. (38); mutton broth, 276 gms. (4); chicken, 85 gms. (40); chicken broth, 425 gms. (3); eggs, 114 gms. (42); butter, 92 gms. (15); milk, 269 gms. (11). Total 98.8 158. 6 11.1 1,925 VEGETABLE FOOD. Bread, 142 gms. (18); biscuits, 57 gms. (20); soda crackers, 28 gms. (49); graham gems, 269 gms. (19); tapioca pudding, 142 gms. (31); sugar, 241 gms. (51); apples, edible portion, 85 gms. (59); Malaga grapes, 78 gms. (62); pears, edible por- tion, 510 gms. (64) . Total vegetable food 62.3 22. 2 G43.6 3,101 38 Table 9. — Foods and nvirients consumed by FranJc Albert, December .5-^0— Continued. Kinds and amounts of food consumed. Nutrients and fuel value. Date. Protein. Fat. Carbo- hydrates. Fuel value. 1898. Dec. 10 rXCLASSIFIED FOOD. Cocoa wine, 113 gms. (35) ; ginger ale, 914 gms. (34) ; calf's-foot jelly, 220 gms. (17); malted milk, 7 gms. (16). Total unclassified food Grams. 13.2 Grams. 0.6 Gi-ams. 174.7 Calories. "lie Total food 174.3 181.4 829.4 5,802 Average per day, animal food . 96.5 65.3 17.5 175.4 17.6 4.5 11.1 588.0 260. 5 2 072 2,842 1182 Average per dav, unclassified food 179.3 197.5 859.6 6,096 The amount of coffee infusion consumed on the different days was as follows: December 5, 857 ^rams; December 6, 1,951 grams; Decem- ber 7, 1,707 j^rams; December 8, 2,431 grams; December 9, 1,427 grams, and December 10, 1,638 grams. On December 6, 617 grams of tea infusion was consumed. None was drunk on the following days. As previousl}" noted, it was possible to observe the diet and col- lect the urine of this subject from noon of the Thursday to noon of the Saturday before the race. This period covered practical!}" the last day of active training and the first da}' of comparative rest before the contest. The results of observations of food consumption for these two days are shown in Table 8, above. On the first day the food con- tained 195 grams of protein (31.2 of nitrogen) and 4,025 calories of energy; on the second, 143 grams of protein (22.9 of nitrogen) and 3,280 calories. During the two days the subject eliminated 24.5 and 14.1 grams of nitrogen, respectively, in the urine (see p. 50). Thus, while the potential energy of the diet was but very little above the averages found for farmers, mechanics, and professional men, and con- sidera]>ly less than the average of college athletes in studies made in the United States,^ the protein was considerably higher than in the former and rather higher than in the latter. It appears, however, that a consid(;rable portion of this protein was stored in the body, since the urine contained much less nitrogen than the food, and the amount in the feces could account for more than a part of this difference. DIETARY STUDY NO. 258, H. PILKINGTON. This study covered the first three days of the I )i cycle race (December 5 to 7, inclusive). The food was prepared in the same way as that served Miller (No. 255), and the same methods were followed in weighing the food consumed and collecting the samples. The details of the dietary study follow: ' U. S. Dept. Agr., Office of Experiment Stations Buls. 21 and 75; also U. S. Deot. Agr. Ycarlxxjk, 1898, p. 450; Connecticut Storrs Sta. Rpt. 1897, p. 153. 39 Table 10. — Foods and nutrients consumed by Henry Pilkington, December 5-7, inclusive. 1 Kinds and amounts of food consumed. Nutrients and fuel value. DatP. Protein. Fat. Carbo- hydrates. Fuel value. 1898. Dee. 5 ANIMAL FOOD. Eggs, 79 gms. (42_); milk, 1,600 gms. (12); koumiss, 4 5''2 gms (13) Total animal food &rams. 223. 6 14.2 Grams. 185. 6 3.0 Grains. 279.6 204.8 Calories. 3,789 VEGETABLE FOOD. Boiled oatmeal, 506 gms. (23); boiled rice, 574 gms. (25); sugar, 89 gms. (51) ; apples, 19 gms. (59). To- 926 Total food 237.8 188.6 484.4 4, 715 ANIMAL FOOD. Vigoral,85 gms. (6); eggs, 46 gms. (42); milk, 1,496 gms. (12); koumiss, 3,233 gms. (13). Total animal Dec. 181.0 9.8 146.5 1.7 224. 208.0 3,023 VEGETABLE FOOD. Boiled oatmeal, 131 gms. (23); boiled rice, 756 gms. (25); sugar, 86 gms. (51); oranges, 255 gms. (63). 909 Total food 190.8 148.2 432.0 3, 9.32 ANIMAL FOOD. Vigoral, 156 gms. (6); butter, 2S gms. (43); milk, 4,165 gms. (12); koumiss, 175 gms. (13). Total an- Dec. 7 156. 5 47.8 189.0 8.9 217. 6 393.7 •\"91 VEGETABLE FOOD. Bread, 307 gms. (45); boiled oatmeal, 768 gms. (23); boiled rice, 350 gms. (25); sugar, 80 gms. (51) ; ap- ples, 150 gms. (59); oranges, 85 gms. (63). Total 1,893 Total food 204.3 197.9 611.3 5,184 187.0 23.9 173.7 4.5 240.4 268.8 3, 368 1,242 210.9 178.2 509.2 4,G10 The amount of coffee infusion consumed on the different days was as follows: December 5, 552 grams; December 6, -±57 grams, and December 7, 605 grams. In the preceding tables the fuel value of the diet was calculated by Rubner's factors, which are in common use. According to these each gram of protein in the average mixed diet has a fuel value of 4.1 calories, each gram of fat 9.3, and each gram of carbohydrates 4.1 calories. These factors were proposed by Rubner in 1885,^ and were based upon such data as were available at the time. A large amount of experimental research has, however, accumulated within recent years which makes it possible to determine these factors with a closer approach to accuracy. Atwater and Bryant recently published an article which contains a general summfiiy ~ of the data bearing upon the determinations of factors for estimating the fuel value of the >Ztschr. Biol., 21 (1885), p. 377. =* Connecticut Storrs Sta. Rpt. 1899, p. 73. 40 various nutrients in different kinds of food materials and in ordinary mixed diet. In the article referred to the factors 4.0, 8.9, and 4.0 are proposed as expressing- much more clearly the average fuel value of 1 gram of protein, fats, and carbohydrates, respectively, than do the corresponding factors of Rubner. In deducing these factors the results of a considerable amount of late experimental inquiry were summarized, including* (1) anal3'ses of over 4,000 specimens of American food materials; (2) a large num- ber of European and American determinations of the nitrogen factor of protein and of the heats of combustion of food materials and of the proteids, fats, carbohydrates, and other compounds occurring in them; (3) a considerable number of determinations of the ratio of the heat of combustion of solids of urine to the amount of nitrogen present including 40 late American determinations of the urine of men sub- sisting upon different diets, made chiefly in connection with digestion experiments; (4) the proportion of different kinds of food materials and of nutrients in the ordinar}' mixed diet, as shown by the results of 185 dietary studies lately made in the United States; and (5) the digestibility of the nutrients of different food materials, as indicated by European and American digestion experiments, including nearly 100 experiments lately" made in the United States on the digestibility of a mixed diet by healthy men. Most of these data have accumulated since Rubner made his estimates in 1885. Thus for the heat of combustion of urine, which is an important factor in determining the fuel value of the protein, he had onl}' the results of a small number of determinations on the urine of dogs. Moreover, Rubner's estimates were based upon determinations of heats of combustion by the Thompson-Stohmann calorimeter, which has been found to give lower results than are obtained b}^ the more highl\' developed bomb calorimeter now commonly used. In discussing the factors for fuel value as proposed by Rubner and those as proposed by Atwater and Bryant, it is necessary to carefully define the terms used. The sense in which the expression "fuel value" is here used is stated in the following definition: "B}" fuel value is understood the energy (heat of combustion) of the material of the food which is capable of oxidation in the bod3^ For the total food it is the total energy less that of the corresponding unoxidized materials of the feces and urine. For the protein it is likewise the total heat of combustion less that of the corresponding unoxidized residues of these excretions. For the fats and carbohy- drates it is the total energy of the food less that of the corresponding unoxidized material of the feces." Rubner's fuel value or "Warmewerth" of protein was obtained in practically the same way as the new factor for the fuel value of pro- tein. In his " Wiii'mewerth " of fats and carbohydrates, however, no 41 allowance was made for the amounts lost in the feces. The difference, therefore, between Rubner's ' ' Warmewerth " and the term fuel value here used is: For the fats and carbohydrates, Rubner's "Warmewerth" is the total heat of ^combustion, whereas the fuel value is that amount less the heat of combustion of the corresponding- compounds of the feces. For the protein the " Warmewerth" and the fuel value both represent the heat of combustion of the total protein,. less the sum of the heats of combustion of the protein of the feces and the solids of the urine. Aside from this difference there is a further variation between Rubner's esti- mates for "Warmewerth" and those here given for fuel value, which has alreadj" been referred to, namely, the smaller values for heats of combustion as determined by the Thompson-Stohmann calorimeter upon which Rubner first based his factors. Nevertheless, it is only just to say that considering the paucity of Rubner's data and the fact that he made no allowance for either the undigested material or the metabolic products of the feces properly belonging to the carbohydrates and fats, the results are certainly very close to those arrived at by the use of the more extensive data now available. The data given in some detail in Tables T, 9, and 10 are summarized in Table 11. This table also gives the fuel value of the food as computed b}^ the old and the new factors. In addition, there are added for pur- poses of comparison, the fuel values actually found b}" experiment. These latter values are in eveiy instance slightl}^ lower than those computed by use of the new factors, and are very much lower than the values as computed b}" use of the old factors. The}" indicate that in these particular cases even the new factors are somewhat too large. These factors, however, were applied to the results obtained in twentj^-seven experiments made in connection with investigations with the respiration calorimeter, and were foiuid on the average to give results differing by only one-tenth of 1 per cent from the actual fuel values as determined by experiment. Table 11. -Suvvnary of nutrients and fuel value of food con.mmed eacJi day by the different riders. Subject and day. Protein. Fat. Carbohy- drates. Fuel By old factors. value. By new factors. MILLER. First day, Dec. 5 Grams. 290 160 235 74 104 152 Grams. 218 144 237 78 168 240 Grams. 533 446 728 419 499 885 Calories. 5,397 3,823 6,151 2,745 4,035 6,477 Calories. 5 ''3'' Second dav, Dec. 6 3 706 Third dav, Dec. 7 5,961 Fourth dav, Dec. 8 Fifth dav, Dec. 9 3,907 6,284 Sixth dav, Dec. 10 Average of 6 days 169 181 585 4,770 4, 626 4 583 Fuel value as actually determined 42 Table 11. — Summanj of nutrients and fuel value of food consumed each day by the different riders — Continued. Subject and day. First day, Dec. 5... Second day, Dec. 6. Third day," Dec. 7.. Fourth day, Dec. 8. Fifth day, Dec. 9... Sixth day, Dec. 10 . Average of 6 days Fuel value as actually determined. PILKINGTON. First day, Dec. 5... Second day, Dec. 6. Third day, Dee. 7.. Average of 3 days Fuel value as actually determined. Protein. Orams. 165 116 188 220 213 174 179 238 191 204 Orams. 200 114 153 282 255 181 198 189 148 198 Carbohy- drates. Orams. 735 641 979 984 989 829 859 484 432 611 Fuel value. By old By new factors, factors. Calories. 5,549 4,161 6,207 7,561 7,299 5,802 6,096 4,715 3,932 5,184 4,610 Calories. 5,380 4,043 6,030 7,326 7,078 5, 623 5,913 5,878 4,570 3,809 5, 022 4,467 4,323 FOOD CONSUMPTION OF THE BICYCLE RACERS COMPARED WITH THAT OF OTHER ATHLETES. The food consumption of these bicycle racers is compared with that of other athletes and of different classes of men at severe and at ordi- nary occupations in Table 12, which follows: Table 12. — Comparison of average daily food consumption of persons with severe muscular work. 3g A" 9 10 11 12 13 14 15 I 16 I 17 j 18 j 19 1 Miller during fi-day race, 1898 Pilkiiigton during'3 days of the 6-day race, 1898... Albert during 6-day race, 1898 Albert during preliminary period, 1898 Weston, 5-day preliminary to 5-day walk, 1870 6 .. Weston during 5-day walking race, 18706 Weston, 5 days following 5-day walking race, 1870 h Weston, ninety-fifth to ninety-ninth day of 100- day walk (> Weston, 3-day walking race, 1877 c Weston, 6-day preliminary to 6-day walking race, 1877 fZ Weston, 6 days of walk, 1877 d Miller during 6-day bicycle race, 1897 e Sandow in time of exliibjtions of strcnglh/ Harvard University boat crew, (^aintiriilKc, 1898 17. Harvard freslur)iin Ixiat crew, Caniliridgc, l.sy.s*;.. Harvard rnivcrsity hoatcri'W, New London, IX'.iKi/ Hin-v:ird frcslunaii hoiit crew, New Lomloii, l.s'jSf/. Captain of Harvard freshman crew. New London, 1898 (7 Yale University boat crew, New Haven, 1898 ^ which agrees with Smeaton's formula. Various other authorities have given different values for the wind pressure, probably because of some condition not noticed or corrected which affected the 1 Kent's Mechanical Engineer's Pocket Book, p. 492. ^The Windmill as a Prime Mover, p. 9. ^Engineering News, July 6, 1890. 58 results. Thus, Marton^ ^ives^> = 0.004 av"^-^ Whipple and Dies, jp = 0.0029 av^\ and Crosby ^^=:0. f ai^ in which /* is a constant to be determined. The weight of evidence would indicate that the wind pressure on plane bodies is very nearly equal to the amount represented by the formula, j9 =0.005 av ^.. The pressure on a rounded body is considerably less than on a flat body; thus the pressure on a cylinder or cone is equal to one-half that of its diametrical planes. Air resistance of rideTS. — The air resistance which a rider must over- come depends upon his body exposure. The data given on pages 20 and 21 show that Miller was 5 feet 4 inches in height, and had a waist measure of 34 inches, while Albert was 5 feet 8i inches in height with a waist measure of 30 inches. One of these men being somewhat the taller and the other somewhat the broader, it seems quite probable that the exposure of each was about the same. This exposure would depend to a considerable extent upon the position in which they rode, it being noticeably smaller in the scorching position than when riding bolt upright. These men are reported to have ridden in a semiupright position, as would probably be necessary because of the prolonged time of the race. The total exposure of a man of similar dimensions riding bolt upright has been found to be about %\ square feet, in the semiupright position 6 square feet, and in a scorching position a little over 5 square feet. The resistance on account of the rounded nature of the body is considered by the best authorities about equal to one- half of that of a plane of equal dimensions. From the authors best calculations the exposed surface in the semiupright position would be equivalent to a plane of about 3 square feet.* At times it is doubtless equivalent to as much as 4 square feet, and during short intervals of scorching was doubtless much reduced. In some previous calculations the author concluded that a small man riding for a short distance could bend his body into such a form that the resistance due to the air would not exceed 1.5 square feet of plane surface.* In the following calcula- tions it has been assumed that the exposure of the riders was equiva- lent to 3 square feet of plane surface. The work done in overcoming the wind resistance is equal to the pressure multiplied by the distance passed through in a given time. 1 Kent's Mechanical Engineer's Pocket Book, p. 492. ''■ Kent's Mechanical Engineer's Pocket Book, p. 493. ^According to unpuljlished results obtained by A. P. Bryant, at Middletown, Conn., the total exposure of a liicycle rider of about the build of Albert, when in different positions, as ascertained by measuring the shadow area, was as follows: When sitting bolt upright it was equal to (j.4 square feet; when sitting semiupright, 5.9 square feet, and in the "scorching" position, 5.2 square feet. *See L. A. W. Bulletin, May, 1898, and Sibley Journal, Dec, 1899, p. 58. 59 Thus if the pressure is expressed by the formula jp — 0.006 av^, the work done in foot pounds per minute, w^ is expressed by the formula ^^ = 0. 005 cm ^ d. From this latter formula the following table of air resistance is constructed, showing the total amount of work done 1 38 000 36 000 34 000 32 000 30 000 U 28000 h 2 26 000 2 24 000 y 22 000 Q. 20 000 UD ^ 18000 D 16 000 [L 14000 h ^ 12 000 L 10 000 8 000 6 000 4000 2 000 — -n n ~^ / / / / / / / / / / / 1 / / / / / / / / t V / / y ^ y ^ . — 3 2 4 6 8 10 12 14 16 18 20 22 24 26 28 3C SPEED IN MILES PER HOUR. Fig. 2. — Curve showing wind resistance for different speeds, expressed in foot-pounds per minute, for 3 square feet of exposed plane surface. per minute with an equivalent exposure of 3 and of 4 square feet. The results expressed in the last two columns of this table are shown graphically in fig. 2. This diagram is more convenient for actual use than the values in the table, as the amounts of work done at rates inter- mediate between those given in the table are readily found. 60 Table 1. — Total air resistance overcome by nders at different sj^eeds. Wind pressure against Work done by riders Speed per hour. Wind pressure per square foot. riders. per minute. Exposure Exposure Exposure Exposure equivalent equivalent equivalent equivalent to i square to 3 square to 4 square to 3 square feet. feet. feet. feet. Miles. Pounds. Pounds. Pounds. Ft. pounds. Ft. pounds. 5 0.125 0.5000 0.375 220 165 n .281 1. 125 .843 743 562 10 . .500 2.000 1.500 1,760 1,320 16 1.125 4.500 3.375 5,940 4,455 20 2.000 7.000 6.000 14, 040 10,530 25 3.125 12.500 9.375 27, 500 20, 625 30 4.500 18.00 13.500 47, 520 35,640 The data here used give onlj^ the average speed for each day, and the results are therefore computed from such information. As the wind resistance increases with the square of the speed, this necessarily makes some error, which may be considered, however, as compensated for by riding in a bent position so as to expose less surface when moving at a high rate of speed. It seems probable from the habits of most riders that such compensation may have occurred; if so, the results will not be greatly in error. WHEEL RESISTANCE. The author has made numerous experiments on various types of bic3^cles to determine the power required to overcome the various mechanical resistances. Quite an extended account of these tests was recenth^ published^ and the results need only be referred to in this article. The friction of the driving mechanism, whether chain or bevel gear, absorbs much less mechanical force than that of the tire. The best grades of chain gear require less mechanical power to propel them than the bevel gear, but considering the great amount of force absorbed by the tire, this difference is not material. The following table shows the work, in foot-pounds, required to over- come the internal (gear and bearing) friction of five grades of wheels, with different amounts of force applied to the pedals, and the corre- sponding percentage of efficiency of the wheels. The results are deduced from a series of experiments. 1 Sibley Journal, Nov. and Dec, 1899, pp. 58, 94. 61 Table 2. — Friciion involved in the driving of various chain and chainlesshicijeles at a s^jeed of 15 miles per hour. Total work per minute. Mean pedal Chain Fric- jear A. Chain gear B and best chainles.s. Chain gear C. Chainless gear No. 1. Chainless gear No. 2. Fric- Fric- Fric- Fric- sure, a tion Effi- tion Effi- tion Effi- tion Effi- tion Effi- min- ciency. min- ciency. min- ciency. min- ciency. per min- ciency. ute. ute. - ute. ute. ute. Ft. lbs. Ft. lbs. Ft. lbs. Per ct. Ft. lbs. Per ct. M. lbs. Per ct. Ft. lbs. Per ct. Ft. lbs. Per ct> 2,500 10.2 50 98 150 94.0 2.50 90.0 208 91.6 783 67.5 5,000 20.4 57 98.8 241 95.8 332 94.3 288 94.25 813 83.8 7, .500 30.6 64 99.2 271 96.4 414 94.5 367 9.5.1 842 88.8 10,000 40.8 71 99.3 331 96.7 496 95.1 469 95.3 893 91.0 12,500 51.0 78 99.4 392 96.9 578 9-5.4 549 96.6 923 92.6 15, 000 61.2 86 99.4 453 97.0 660 95.6 640 95.7 965 93.6 17,500 71.4 93 99.5 514 97.1 742 95.7 723 95. 85 997 94.4 20,000 81.6 100 99.5 575 97.2 825 95.8 812 9.5.94 1,037 94.8 25,000 102.2 107 99.6 636 97.3 907 96.2 875 96.5 1,040 95.9 a Mean pedal pressure for wheel with e^-inch crank and with 70f gear. The following- table shows in a similar manner the amount of work lost because of the friction of the tire on a sing-le wheel when working under conditions similar to those under which the data in the preced- ing table were obtained. In estimating the total resistance of the bicy- cle, the results in this table should be doubled and added to the internal resistances as given in the preceding table. T.\BLE 3. -Tire friction of rear wheel at a speed of 15 miles i^er hour, with different amounts of total ivork. Total work per minute. Mean pedal pres- sure.a Very thin racing tire. Heavy racing tire. Light road tire. Ordinary road tire. Friction per min- ute. Effi- ciency. Friction per min- ute. Effi- ciency. Friction i ■„.«, ! Friction per min- ute. Effi- ciency. Ft. lbs. 2,500 5,000 7,500 10,000 12,500 15,000 20,000 25,000 Ft. lbs. 10. 22 20.4 30.6 40.8 51.0 21.2 81.6 102.2 Ft. lbs. 525 608 691 - 774 858 941 1,025 1,108 Per ct. 79.0 87.8 90.8 '92.3 93.2 93.7 94.8 95.6 Ft. lbs. 1,156 1,219 1,282 1,345 1,408 1,471 1,534 1,596 Per ct. 53.8 76.7 82.8 86.6 88.8 90.2 92.2 93.6 Ft. lbs. 1,626 1,696 1,767 1,838 1,909 1,980 2, 1.50 2, 221 Per ct. 35.0 66.0 75.5 81.6 84.8 86.8 89.2 91.9 Ft. lbs. 2,000 2,108 2,216 2,324 2,432 2,541 2,650 2,758 Per ct. 20.0 57.8 70.6 76.7 80.6 83.2 86.7 88.9 a Mean pedal pressure for wheel with crank 6i inches long and with 70 J gear. The above results were obtained by deducting from the friction of the entire wheel, with tire, the friction of the same wheel without tire. It is quite probable that the riders in the six -day races would select the best grades of bicycles and those which were propelled with the least expenditure of power. The author has found that riders are generally expert in selecting wheels which have the least friction. Hence it appears that it is fair to assume that the force required to propel the wheels would correspond to the lowest results in Table 3, and those next lowest in Table 2. This latter supposition is believed to be rather more probable, for the reason that the lowest results in Table 2 are to be considered as exceptional. 62 For the purpose of facilitating- computations of results a diagram (fig. 3) has been prepared, on which is shown the resistance in foot- pounds per minute due to gearing and also to the best racing tire, cor- responding to a total resistance which is given at the bottom of the diagram. This diagram is constructed for a speed of 15 miles per hour. For a speed greater than 15 miles the resistance is increased in each case by an amount which was determined by test and was equal to the amount given in the table multiplied b}^ one-ninetieth of the increase in speed. Thus, if the amount in excess of 15 miles per hour be de- noted b}^ X, the increased resistance would be that given in the diagram times X, which is to be added to the value obtained from the diagram. Experiments made in Sibley College laboratory show that for a differ- ence in weight of 15 pounds the total resistance does not increase more .1250 U ^1000 CCLJ b-D- „500 ^8250 OQ. ~^ ~^ n . — — — •^ — ' TRi fA St£ ?A( ^ n . — — — ^ fW ^ . - . — — '" , , ' f ^ IaBI X' J. — fa aFn G V\h - -- -— -^ "' EOOO 4000 6000 8000 lOOGO 12000 14000 16000 18000 20000 ?2000 24000 26000 28000 TOTAL WORK. FOOT POUNDS PER MINUTE Fig. 3. — Curves showing bicycle resistance, speed 15 miles per hour. than 2 per cent. As this correction is smaller than the probable error of computation, it has not been considered best to make use of it. From data given earlier in this bulletin (pp. 23-27) we know the distance ridden each day and the time spent in riding, from which we may compute the average speed per hour. By use of figs. 1 and 2 the total resistance due to gear and tire friction and to wind pressure may be computed. These results are shown in Tables 1 and 5. The values in the fifth column for resistance due to wind pressure are taken directly from fig. 2 at the average speed per hour. Those in the fifth column, bicycle resistance, are found from fig. 3 in the fol- lowing manner: The total resistance will be equal to the wind resist- ance plus the gear resistance and the tire resistance^ of both wheels. 1 In the computation for the total resistance of the bicycle the friction work of the gearinj; and the friction work of the two wheels have been added. In a previous cal- culation, to which reference has been made, the total wheel resistance was taken as that of th(! Snyder and L. A. Voorhees. Pp. 51. Price, 10 cents. A Description of Some Chinese Vegetable Food Materials and Their Nutri- tive and Economic Value. By AV. C. Blasdale. Pp. 48. Price, 10 cents. Experiments on the Metabolism of Matter and Energy in the Human Body. By W. O. Atwater and F. (1. Benedict, with the cooperation of A. AV. Smith and A. P. Bryant. Pp. 112. Price, 10 cents^. Dietary Studies of Negi-oes in Eastern Virginia in 1897 and 1898. By H. B. Frissell and Isabel Bevier. Fp. 45. Price, 5 cents. Dietary Studies of University Boat Crews. By AV. 0. Atwater and A. P. Bryant. Pp. 72. Price, 5 cents. Nutrition Investigations at the California Agricultural Experiment Station, 1896-1898. By M. E. Jaffa. Pp. 39. Price, 5 cents. A Report of Investigations on the Digestibility and Nutritive A^alue of Bread. By Chas. D. Woods and L. H. Merrill. Pp. 51. Price, 5 cents. Experiments on the Effect of Muscular \A"ork upon the Digestibility of Food and the MetaboUsm of Nitrogen. Conducted at the Universitv of Tennessee, 1897-1899. By C. E. Wait. Pp. 77. Price, 5 cents. Nutrition Investigations at tlie Universitv of Illinois, North Dakota Agri- cultural College, and Lake Erie College, Ohio, 1896-1900. By H. S. Grindley and J. L. Sammis, E. F. Ladd, and Isabel Bevier and Elizabeth G. Sprague. Pp. 42. Price, 5 cents. farmers' bulletins. Bui. 23. Foods: Nutritive A^alue and Cost. By AV. O. Atwater. Pp.32. Bui. 34. Meats: Comiwsition and Cooking. Bv C. D. AVoods. Pp. 29. Bui. 74. Milk as Food. Pp. 39. Bui. 85. Fish as Food. By C. F. Langworthy. Pp. 30. Bui. 93. Sugar as Food. By Mary H. Abel. Pp. 27. Bui. 112. Bread and the PrineiiDles of Bread Making. By Helen AV. Atwater. Pp.38. Bui. 12]. Beans, Peas, and other Legumes as Food. By Mary H. Abel. Pp. 32. Bui. 128. Eggs and Their Uses as Food. By C. F. Langworthy. Pp. 32. CIRCULAR. Cir. 46. Foods for Man. By C. F. Langworthy. Pp. 10. SEPARATES. Food and Diet. By W. O. Atwater. Reprinted from Yearbook of Department of Agriculture for 1894. Pp. 44. Some Results of Dietary Studies in the United States. By A. P. Bryant. Reprinted from Yearbook of Department of Agriculture for 1898. Pp. 14. ])evelopment of the Nutrition Investigations of the Department of Agriculture. By A. C. True and R. D. Milner. Reprinted from Yearbook of Department (.f Agriculture for 1899. 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