If the interest of a scientific expositor ought to be…

““If the interest of a scientific expositor ought to be measured by the importance of the subject, I shall be applauded for my choice. In fact, there are few questions which touch more closely the very existence of man than that of animated motors—those docile helps whose power or speed he uses at his pleasure, which enjoy to some extent his 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?””

— Etienne-Jules Marey