A single class of insects, a single family of plants, the habits of one race of fishes, suffice for the exclusive study of half a lifetime.

Minds of a more active or more practical bent will spend an equal time over the construction of a new machine more absolutely automatic than any that has preceded it.

Physical labour is thrown as much as possible on the young; and even they are now so helped by machinery and by trained animals, that the eight hours' work which forms their day's labour hardly tires their muscles.

Our tastes render us very anxious to devolve upon others as soon as possible the preservation and development of the property we have acquired.

A man of moderate means, long before he has reached his thirtieth [7] year, generally seeks one assistant; men of larger fortune may want two, five, or ten.