Let our attention be directed a little while to the effects of the privation of knowledge, as they may be seen conspicuous in the several parts of the economy of life, in the uneducated part of the community. Observe those people in their daily occupations. None of us need be told that, of the prodigious diversity of manual employments, some consist of, or include, operations of such minuteness or complexity, and so much demanding nicety, arrangement, or combination, as to necessitate the constant and almost entire attention of the mind; nor that all of them must require its full attention at times, at particular stages, changes, and adjustments, of the work. We allow this its full weight, to forbid any extravagant notion of how much it is possible to think of other things during the working time. It is however to be recollected, that persons of a class superior to the numerous one we have in view, take the chief share of those portions of the arts and manufactures which require the most of mental effort,--those which demand extreme precision, or inventive contrivance, or taste, or scientific skill. We may also take into the account of the allotment of employments to the uncultivated multitude, how much facility is acquired by habit, how much use there is of instrumental mechanism, (a grand exempter from the responsibility that would lie on the mind,) and how merely general and very slight an attention is exacted in the ordinary course of some of the occupations. These things considered, we may venture perhaps to assume, on an average of those employments, that the persons engaged in them might be, as much at least as one third part of the time, without detriment to the manual performance, giving the thoughts to other things with attention enough for such interest as would involve improvement. This is particularly true of the more ordinary parts of the labors of agriculture, when not under any critical circumstances, or special pressure owing to the season.