J19 



ANIMAL STRENGTH. 



ANIMAL SUBSTANCES. 



360 



flight of steps unloaded, the vertical heights of all the ascents during 

 one day being added together, were equal to 1'82 mile ; the quantity 

 of action may therefore be expressed by 160 x 1'82 or 291, as if the 

 action were equivalent to that of a machine which could raise 291 Ibs. 

 to the height of 1 mile vertically, or one pound to the height of 291 

 miles during a day. When loaded with 150 Ibs. the vertical height 

 ascended was 0'494 mile : the whole quantity of action is, therefore, 

 in this case (160 + 150) x 0'494, or 153, while the useful effect is 

 150 x 0'494, or 74 ; that is, 74 Ibs. raised 1 mile vertically. 



It is remarkable that, from the result of Coulomb's experiments on 

 the power of men ascending steps, both the greatest weight which a 

 man can carry without moving, and the weight which he should bear 

 to render his useful effect a maximum, are nearly the same in this case 

 as they were found to be from experiments made with burdens carried 

 on level ground. 



Coulomb has also made experiments to determine the quantity 

 of action in the case which most generally occurs when heavy goods 

 are carried in towns, viz. that in which a porter, having delivered his 

 burden, returns unloaded for another ; and his conclusion is, that, in 

 order to produce the most useful effect in this case, the greatest 

 burden which a man should carry on level ground is 135 Ibs., and with 

 this he should walk seven miles. The quantity of useful action is 

 therefore 135 x 7, or 945. 



It is said that a London porter can carry 200 Ibs. on his shoulders at 

 the rate of three miles per hour ; but this action can only be continued 

 during a short time. 



The following statements of the strength of men are taken from 

 Hachette's ' Traitc* des Machines,' and from other source* ; the 

 numerical values being reduced so as to express the number of pounds 

 carried by a man one mile per day of eight hours : 



Drawing a vessel on a canal 753459 



Conveying a load (110 Ibs.) in a wheelbarrow (1'018 



mile per hour) 89(5 



Drawing a small waggon on four wheels over rather 



unequal ground 857 



Pulling horizontally, the weight being raised by a 



rope passing over a pulley .... . 378 



Rowing in a boat :; 7l 



Thrusting horizontally, as at a capstan . . . . 368 



Turning a winch and axle 159 



Digging with a spade . . . . . 85'3 



A soldier marching (12*43 miles) with his anus, &c. 



i') Ibs.) daily 745 



V ith respect to the horse, the most useful way of employing his 

 strength is to make him draw loads in a cart or waggon; but, even 

 for such work, the estimates which have been made of the quantity of 

 action performed daily are various. 



According to Tredgold a horse can draw 125 Ibs. at the rate of 

 2J miles per hour, which, for one day, would give 125 x 2J x 8, or 

 J.~ioo. But Messrs. Boulton and Watt ascertained from trials, pur- 

 posely made, that a strong horse can draw 125 Ibs. at the rate of 

 3 miles per hour ; and the measure of the power of such a horse is 

 3000, which expresses a number of pounds drawn one mile in a day. 

 If this be multiplied by the number of feet in a mile, and the product 

 be divided by the nuii(ber of minutes in eight hours, the result 

 ( = 33000) denotes a weight in pounds drawn one foot per minute 

 during the eight hours ; and that result is now universally adopted 

 as a measure of the power of a horse. 



The useful effect of a horse when walking in a circle, 



as in some mills, is considered as equivalent to . 800 

 A horse carrying a soldier with arms, &c. ( = 200 Ibe.), 



can go 25 miles in a day, which gives . . . . 5000 

 An African dromedary carrying only his rider (160 Ibs.) 

 can go between seven and eight miles per hour 

 during nine or ten hours, which gives 160 x 74 x 



94, or 11400 



An Asiatic camel will carry burdens weighing from 



. 800 Ibs. (suppose (W>) at the rate of two and 



a half miles per hour. This, for a day of eight hours, 



gives 600 x 24 x 8, or 12000 



The velocity of a horse in walking is estimated at 54 f 66 * per second, 

 or 3 j miles per hour ; in trotting 12 feet per second, or 8J miles per 

 hour ; and in galloping 18 feet ]>er second, or 12J miles per hour. 



The following remarks are taken from Major Griffiths's ' Artillerists' 

 Manual ' : The average weight of artillery horses is 10 cwt. 2 qrs. 

 The most useful mode of applying a horse's power is in draught, and 

 the worst is in carrying a load. This is owing to the structure of the 

 animal. It has been found that three men carrying each 100 Ibs. will 

 ascend a hill with greater rapidity than one horse carrying 300 Ibs. 

 WIn'ii ,i horse has a large draught in a waggon, however, it is found 

 1 to load his back to a certain extent ; this prevents him from 

 inclining no much forward, as he would otherwise do, and consequently 

 fr*e him from the fatigue of great muscular action. The best dis- 

 position of the traces in draught is when they are perpendicular t< 

 the collar ; when the horse stands at ease, the traces are then inclined 

 to the horizon, at an angle, of about 15 ; but when he leans forward 

 to draw, the traces should then become nearly parallel to the road. 

 The most pi-oppr inclination. ln,v..'v, i . \ ; determined from the relation 



which subsists between the friction and the pressure in every particular 

 case. When a horse is employed in moving a machine, by travelling 

 in a circular path, the diameter ought not to be less than 25 or 30 feet, 

 and iu most cases 40 feet should be preferred ; at all events, it must 

 :iot be less than 18 feet. 



The following table shows the mn.cimum quantity of labour which a 

 lorse of average strength is capable of performing at different velocities, 

 on canals, railways, and roads, but in comparing this table with practice 

 at the higher velocities, it is found necessary to add one-third more 

 than the useful effect for the total mass moved. Whatever the diffi- 

 culties of a road may be, ten horses are as many as can be harnessed 

 with effect to one carriage. 



The following is the result of experiments with a light four- 

 wheeled cart, weighing, with its load, 1000 Ibs., drawn on different 

 sorts of roads (124 ^ Da - being deducted from the force of traction, 

 for the friction at the axles, which were of wood) : 



Force of traction. 

 Turnpike road, hard and dry . . . .18 



dirty 264 



new gravelled .... 130J 

 Loose sandy road . 191J 



NOTE. An ox can draw about 4 cwt., and a pair of oxen 9 cwt. 

 on a level road. 



ANIMAL SUBSTANCES. Among the important and indispensable 

 materials of manufactures, are those which are derived from the animal 

 kingdom. Few persons are aware, unless actually eugaged in manu- 

 facturing operations, how numerous and varied these materials are. 

 The bounty of nature lias placed at the disposal of man so large a 

 number of substances, derived from so large a number of animals, that 

 there is scarcely an article in daily use but can exhibit an application of 

 some such substance, either in its formation or its decoration. The 

 exterior and the interior, the solids and the liquids all parts of some 

 animals, and numerous parts of many, admit of being thus industriously 

 applied. 



In the classified list of objects drawn up for the Commissioners of 

 the Great Exhibition of 1851, the principal materials of manufactures 

 and the arts derived from the animal kingdom were enumerated, and 

 an attempt was made to arrange them into some convenient systematic 

 form. In the first place, the whole series was divided into three 

 sections, namely ; 1st, Animal substances used as food ; 2nd, Animal 

 substances used for medicinal purposes ; and 3rd, Animal substances 

 used in manufactures. 



Almost every part of almost every species of animal serves as food to 

 some variety or other of the human race. The flesh, the eggs of birds, 

 and the milk of mammalia, are obviously the chief forms in which 

 animal food is presented ; but there are many other forms to which 

 more or less of preparative process has been applied ; such as preserved 

 meats for long voyages ; portable soups ; concentrated nutriments ; 

 consolidated milk ; dried gelatine, albumen, and isinglass ; caviare and 

 trepang ; sharks' fins ; nests of the Java swallow ; honey, &c. 



The animal substances used in the medicinal art are exceedingly 

 numerous. Among them are cod-liver and other animal oils ; unguents 

 of spermaceti, lard, oil, and various combinations of the three ; musk, 

 castoreum, civet, and ambergris ; phosphorus and ammonia, from 

 bones and hartshorn ; crabs' eyes (the calcareous concretions foi'ined in 

 the craw-fish), and cuttle-bone; cantharides, and their essence cau- 

 tharadine ; iodine, obtained from marine zoophytes and sponge, &C. 



But the animal substances used in manufacturing processes, though 

 perhaps not equalling in quantity those consumed aa food, are far more 

 varied iu quality and texture. They are so numerous that the Com- 

 missioners found it convenient to separate this section into five 

 divisions, namely ; Animal substances employed, 1st, for textile fabrics 

 and clothing ; 2nd, for domestic or ornamental purposes ; 3rd, for 

 serving as agents in the manufacture of other articles ; 4th, for the 

 production of chemical substances ; and 5th, for pigments and dyes. 

 Under the first division come wool, hair, hair bauds and ropes ; bristles 

 and whalebone ; silk from the silkworm, the pinna, and other insects ; 

 feathers, down, and fur ; skins, hides, and leather ; elytra or beetle 

 wings, for ornaments of dress, &c. Under the second division are 

 included bone, horn, hoofs, ivory, tortoise-shell, shagreen, parchment, 



