n, animals, or machines; and are wholly independent of
the way in which the power is applied: whether, for instance, a man
carries his burden, or draws it, or rows or punts it in a boat, or winds
it up with a crank or tread-mill.

Travellers might well turn the theory to account on their own behalf;
they are well situated for testing its truthfulness, by observing the
practices of the countries in which they are travelling. Reliable facts
upon the extreme distances that can be travelled over, day after day, by
people carrying different loads, but equally circumstanced in every other
respect, would be very acceptable to me.

The formulae are as follow:--Let b be the burden which would just
suffice to prevent an animal from moving a step; d the distance he could
travel daily if unloaded. Also, let b1 be some burden less than b; and
let d1 be the distance to which he could travel daily when carrying b1.

Then b1 d2 = b(d-d1)2. (1)

Again, the "useful effect" is a maximum, if b1d1 is a maximum. When
this is the case, then

b1 = 4/9 b. (2)
And
3 d1 = d. (3)

In other words, an animal gets through most work in the day if he carries
4/9 of the greatest load he could just stagger under; in which case he
will be able to travel 1/3 of the distance he could walk if he carried no
load at all. (Machinery requires no repose; and therefore d, the distance
per day, is convertible into v, the velocity of movement.)

As an example:--Suppose a man is able to walk 10 miles a day, with a load
of 130 lbs., and 33 miles a day when he carries nothing. Then, from
equation (1), the value of b (the burden under which he would be brought
to a standstill) would be about 267 1/2; and the best load for him, from
equation (2), would be 119 lbs., which he would be able to carry,
according to equation (3), 11 miles a day.

Horses.--The mode of taking wild horses is by throwing the lasso, whilst
pursuing them at full speed, and dropping a noose over their necks, by
which their speed is soon checked, and they are choked down.

Mr. Rarey's sixpenny book tells all that can be told on the subject of
horse-breaking; but far more lies in the skill and horse-knowledge of the
operator, than in the mere theory. His way of mastering a vicious horse
is by taking up one fore-foot, bending the knee, slipping a loop over the
knee until it comes to the pastern-joint, and then fixing it ti