378 THE EXTERIOR OF THE HORSE. 



upon the ground. On the other hand, a photographic apparatus is stationed 

 upon another axis perpendicular to the first. As soon as the animal is placed in 

 a good position, and his members are in their normal equilibrium, the photo- 

 graph is instantaneously taken. 



The photographic proof thus obtained is in some measure a mathematical 

 reduction of the silhouette, or the profile of the subject, and the measurements 

 previously taken upon the latter, then compared to the corresponding dimensions 

 of the photograph, show exactly the ratio of the reduction effected. To avoid 

 the causes of error inherent to the slight alteration of forms due to the lenses, 

 the photographic apparatus is placed at a certain distance, in such a manner as 

 to obtain as small an image as possible. 



Upon this image the wafers serve as so many points of determination or 

 landmarks which it will be sufficient to join by straight lines to obtain the real 

 direction of the osseous segments. It only remains now to estimate with a pro- 

 tractor the inclination of each line, as well as the angles which are formed by 

 their union. With this new process we can measure quietly, at our ease, without 

 fatigue, without danger, and whenever convenient. The measurements are all 

 comparable, since all the angles of the same subject have been photographed at 

 the same time, and since on different horses we operate constantly under the same 

 conditions. 



The results obtained are very analogous to those already indicated. 



What we have said with regard to each region, concerning the 

 osseous inclination and the angular relations, excuses us from entering 

 here into more minute details relative to the numerous variations which 

 are observed in subjects according to their adaptation. 



We will not speak of draught-horses used for slow work, in which 

 the service at a walk requires only bulk and muscle ; their scapulo- 

 humeral and coxo-femoral angles are always more open ; the others, 

 on the contrary, are more closed. When the researches of M. Le- 

 moigne appeared, Professor Neumann was the only one who submitted 

 them to a judicious analysis; and as the criticisms which he opposed 

 to them have an important value and may equally occur to the mind 

 of the reader, it is our duty to give an account of them, inasmuch as 

 they apply to us also who have, since the beginning, sided with our 

 Milan colleague. 



M. Neumann has reasoned upon these things in a purely math- 

 ematical light, and, in this respect, no objection can be made to his 

 deductions. But the case is entirely different if the researches of 

 M. Lemoigne and our own are considered as a very accurate means 

 of obtaining information upon the different inclinations of the bones 

 of fast horses. It is no longer a problem to know if these in- 

 clinations can be calculated with strict precision, a precision which 

 it is impossible to realize in the researches which have animal 

 mechanics for their object ; it practically resolves itself into this : // 



