ON PHOTOGRAPHIC RECORDS OF lEDIGREE STOCK. GOl 



on hard ground, that the feet niray be clearly shown, and no mistake 

 arise about their heights. The height of the camera above the 

 ground and its distance from the animal should be roughly measured 

 and noted. Lastly, two direct measurements of the height of the animal 

 should be made, one at its withers, the other at its croup. The photo- 

 graph now becomes more than a mere picture, because the recorded data, 

 together with others afforded by the photograph itself, supply corrections 

 that will cause the measurements made upon it to correspond with more 

 or less accuracy to those made on the animal itself. Of course, their 

 correspondence would not be so exact as it would be in photographs 

 taken in a ' hippometric ' laboratory provided with marked lines on the 

 ground and walls, but such a laboratory is impracticable on many grounds. 

 Thoroughbred horses are so easily frightened in unfamiliar places and 

 at unfamiliar objects that the best plan is to photograph them leisurely 

 among their accustomed surroundings. It is difficult and dangerous to 

 apply tapes and calipers, which tickle and irritate, for thoroughbred 

 horses are exceedingly sensitive, timid, fidgety, and often vicious, while 

 they are supple and sudden in their movements of offence. Measurements 

 of the two vertical heights, made in the usual way, are comparatively easy 

 to manage. 



I find, moreover, that vertical measurements of all kinds may be made 

 quickly and accurately without touching the objects at all, by means of a 

 simple instrument which I roughly put together for trial. [I submit its 

 working part.] Its principle is that of a collimator, with additions and 

 modifications. It seems very suitable for use at agricultural and other 

 shows where many animals are collected. 



Though many useful measurements can be made on a plain photo- 

 graph, it would be a decided gain to select two, three or more important 

 osseous protuberances, such as can be easily felt, and to mark their positions 

 by sticking on the animal small wafers of sufficiently adhesive paper — say, 

 one quarter of an inch in diameter. The corresponding marks on the 

 photographs will be too small to attract notice, but they are easily found 

 •when looked for, and afford excellent points from which to measure. I 

 may add that measurements I have made, and had made, both on horses 

 and on their photographs, show that the relative dimensions of horses 

 difier considerably. If some five different measurements were made on an 

 adult racehorse, it would be as easy to identify him by a ' Bertillon 

 process ' as it is to identify prisoners. 



It will be observed that the measured height of the animals at the 

 wither and croup, supply a scale for vertical measures on the photograph 

 at those points. If the line to which vertical measures are drawn on the 

 photograph be the one that touches the edge of the feet nearest to the 

 camera, a slight and simple correction has to be made. There is difficulty 

 in respect to the relation between the vertical and the horizontal scales, 

 but less so than might he anticipated, for the tilt of the camera is found 

 closely enough by a rough knowledge of the height of the camera and its 

 distance from the animal, combined with data supplied by the photograph 

 itself. Again, the length between the rounded ends of the body, and the 

 diameters of the limbs, are not sensibly affected by the animal standing 

 very slightly askew. The necessary corrections admit of being easily 

 found from appropriate tables. It is curious in how many different ways 

 the required corrections may be determined when the range of available 



