Different volumes will naturally appeal to different readers. The amateur conjurer will naturally find most to interest him in the volume on Chemistry and Chemical Magic; the budding airmail will turn with more zest to the volume on Aeronautics; the future engineer to that on Mechanics and Mechanical Appliances. What is important is that each boy should be encouraged in his proper bent. Every boy, like my Uncle Toby, should ride a hobby-horse of some kind; and an acquaintance with some branch of science, even if sought at first with no other end than recreation, will be a delight in itself, and may prove a stepping-stone to higher things. In conclusion, if a word of advice may be addressed directly to the boy reader, it is this: Never be content , merely to read about an experiment; that is, to see it only through the mind of the writer and the artist.
Always perform it yourself, even if at first in a manner more or less crude: that is to see it with your own mind—the only real way to see it at all; you have made it your experiment and your knowledge. No man can take it from you; it is yours for all time.