124 
LECTURES ON HORSES. 
wards at rates correspondent with the impetus generated by these 
movements. 
When once set in motion, like the wheels of a carriage, the 
limbs instinctively continue in similar action or pace until some 
fresh mandate is received by them from the sensorium, that be- 
coming the signal for some change in the action or pace. The rate 
the animal is moving at is either augmented or diminished, or his 
movements are altogether arrested, at his own will and pleasure. 
And though his master, as his rider or driver, may assume the 
controul over them during the animal’s working hours, yet could 
neither rider nor driver effect any thing without the assent of the 
animal himself ; and it is ever a great deal best to obtain this 
assent through kind and conciliatory treatment than to extort it 
through ill usage. 
Plain and evident as the movements of the quadruped may 
appear to the common observer, passing as they do every day 
under his immediate observation, yet have they furnished a theme 
for difference of opinion, not less in former days than in our own. 
Borelli, who commences his chapter De Incessu Quadrupedum 
with the remarkable words, “ Egregie in hac parte allucinantur, 
nedum vulgares homines, sed etiam prseclari philosophi et anato- 
mici ; qui potius falsae opinioni per manus traditse, quam pro- 
priis oculis fidem prsestare volunt,” is the first to fall into error. 
The movements of the biped are simple and self-evident ; they 
consist of the alternate advance of the legs, and of the reciprocal 
shifting of the centre of gravity from one to the other : here there 
can be no dispute about priority or order of movement. When 
we have four in place of two legs, however, the case becomes ma- 
terially altered. It is an easy matter to watch two legs ; but it is 
difficult, nay, in quick movements impossible, to keep the eyes 
so fixed upon the motions of four as to say in what order of suc- 
cession they are actually moving or treading the ground. In order, 
however, that we may come at that through inference which we 
cannot derive from actual observation, we will commence with an 
examination of the slowest movement of all — the walk — and from 
that proceed to those next quick in succession, the slow or dwell- 
ing trot, the hand-canter or slow gallop ; and, as we proceed, consi- 
der the changes, if any, that take place under augmentation of 
speed in these respective paces. 
Notwithstanding Borelli’s prefatory denunciation of the philoso- 
phers and anatomists of his own day, for pinning their faith on 
others’ sleeves rather than look with their own eyes, he himself, as I 
said before, appears in error even in his very first observation. After 
shewing the parallelogramical figure of which the horse’s legs, as 
they stand in their natural position, form the four respective angles, 
