and the plan flashed into his mind, how must his eye have brightened, and how quick must the weary listlessness of his employment have vanished.  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.  Contrive a new machine, and every body will be interested to witness or to hear of its operation.  Develop any heretofore unknown properties of matter, or secure some new useful effect from laws which men have not hitherto employed for their purposes, and the interest of all around you will be excited to observe your results; and, especially, you will yourself take a deep and permanent pleasure in guiding and controlling the power you have thus obtained.

This is peculiarly the case with experiments upon mind, or experiments for producing effects through the medium of voluntary acts of others, making it necessary that the contriver should take into consideration the laws of mind in forming his plans.  To illustrate this by rather a childish case:  I once knew a boy who was employed by his father to remove all the loose small stones, which, from the peculiar nature of the ground, had accumulated in the road before the house.  The boy was set at work by his father to take them up, and throw them over into the pasture across the way.  He soon got tired of picking up the stones one by one, and so he sat down upon the bank to try to devise some better means of accomplishing