end, the force which is exerted acts
at the other end, and the weight is in the middle. In trying, these
simple experiments, the terms _fulcrum_, _centre of motion_, &c.
should be constantly employed, and in a very short time they would be
as familiar to a boy of eight years old as to any philosopher. If for
some years the same words frequently recur to him in the same sense,
is it to be supposed that a lecture upon the balance and the lever
would be as unintelligible to him as to persons of good abilities, who
at a more advanced age hear these terms from the mouth of a lecturer?
A boy in such circumstances would appear as if he had a genius for
mechanics, when, perhaps, he might have less taste for the science,
and less capacity, than the generality of the audience. Trifling as it
may at first appear, it will not be found a trifling advantage, in the
progress of education, to attend to this circumstance. A distinct
knowledge of a few terms, assists a learner in his first attempts;
finding these successful, he advances with confidence, and acquires
new ideas without difficulty or disgust. Rousseau, with his usual
eloquence, has inculcated the necessity of annexing ideas to words; he
declaims against the splendid ignorance of men who speak by rote, and
who are rich in words amidst the most deplorable poverty of ideas. To
store the memory of his pupil with images of things, he is willing to
neglect, and leave to hazard, his acquirement of language. It requires
no elaborate argument to prove that a boy, whose mind was stored with
accurate images of external objects, of experimental knowledge, and
who had acquired habitual dexterity, but who was unacquainted with the
usual signs by which ideas are expressed, would be incapable of
accurate reasoning, or would, at best, reason only upon particulars.
Without general terms, he could not abstract; he could not, until his
vocabulary was enlarged, and familiar to him, reason upon general
topics, or draw conclusions from general principles: in short, he
would be in the situation of those who, in the solution of difficult
and complicated questions relative to quantity, are obliged to employ
tedious and perplexed calculations, instead of the clear and
comprehensive methods that unfold themselves by the use of signs in
algebra.

It is not necessary, in teaching children the technical language of
any art or science, that we should pursue the same order that is
requisite in teaching th