While he was maturing his plan and carrying it into execution--while adjusting his wires, fitting them to the exact length and to the exact position--and especially when, at last, he began to watch the first successful operation of his contrivance, he must have enjoyed a pleasure which very few even of the joyous sports of childhood could have supplied.
It is not, however, exactly the pleasure of exercising _ingenuity in contrivance_ that I refer to here; for the teacher has not, after all, a great deal of absolute _contriving_ to do, or, rather, his _principal business_ is not contriving.

The greatest and most permanent source of pleasure to the boy, in such a case as I have described, is his feeling that he is accomplishing a great effect by a slight effort of his own; the feeling of _power_; acting through the _intervention of instrumentality_, so as to multiply his power.

So great would be this satisfaction, that he would almost wish to have some other similar work assigned him, that he might have another opportunity to contrive some plan for its easy accomplishment.
Looking at an object to be accomplished, or an evil to be remedied, then studying its nature and extent, and devising and executing some means for effecting the purpose desired, is, in all cases, a source of pleasure; especially when, by the process, we bring to view or into operation new powers, or powers heretofore hidden, whether they are our own powers, or those of objects upon which we act.

Experimenting has a sort of magical fascination for all.

Some do not like the trouble of making preparations, but all are eager to see the results.