intimacy, and accompany him in his labors and his pleasures. The species of animal whose coöperation we borrow are numerous, and vary according to latitude and climate. But whether we employ the horse, the ass, the camel, or the reindeer, the same problem is always presented: to get from the animal as much work as possible, sparing him, as far as we can, fatigue and suffering. This identity of standpoint will much simplify my task, as it will enable me to confine the study of animated motors to a single species: I have chosen the horse as the most interesting type. Even with this restriction the subject is still very vast, as all know who are occupied with the different questions connected therewith. In studying the force of traction of the horse, and the best methods of utilizing it, we encounter all the problems connected with teams and the construction of vehicles. But, on a subject which has engaged the attention of humanity for thousands of years, it seems difficult to find anything new to say.
If in the employment of the horse we consider its speed and the means of increasing it, the subject does not appear less exhausted. Since the chariot-races, of which Greek and Roman antiquity were passionately fond, to our modern horse-races, men have never ceased to pursue with a lively interest the problem of rapid locomotion. What tests and comparisons have not been made to discover what race has most speed, what other most bottom, what crossings, what training give reason to expect still more speed?
Lastly, as to what is called the exterior of the horse, and his varied paces, specialists have for long devoted themselves to this department. The horseman is trained to distinguish between these different paces, to correct by the education of the horse those which seem to him defective, to fix by habit those which give to his mount more pleasant reactions or a much greater stability. The artist, in attempting to represent the horse, seeks to transfer his attitudes more and more faithfully, to express better and better the force, the suppleness, and the grace of his motions.
These questions, so complicated, I wish to bring before you by a new method, and I hope to show you that the graphic method makes light of difficulties which seem insurmountable, discerns what escapes the most attentive observation; finally, it expresses clearly to the eyes and engraves upon the memory the most complicated notions. The graphic method was almost unknown twenty-five years ago; to-day it is widespread. Thus, in almost all countries, recourse is had to the employment of graphic curves as the best mode of expression to represent clearly the movement of administrative, industrial, and commercial statistics. In all observatories apparatus known as registering or recording, trace on paper the curves of variation of the thermometer, the barometer, rain, wind, and even atmospheric electricity. Physiology utilizes still more largely recording apparatus; but I shall only require to show you a very small number of these instruments, those