The indirect influence, too, of a general advance in knowledge upon the particular advance of any branch of labour, is undeniable;--for the inquiring spirit of an age spreads itself on all sides, and improvement is carried into the most obscure recesses, the darkest chinks and corners of a nation. It has been wisely and beautifully said, "We cannot reasonably expect that a piece of woollen cloth will be wrought to perfection in a nation which is ignorant of astronomy, or where ethics are neglected."[25] The positive influence of science in the direction of labour is chiefly exhibited in the operations of mechanics and chemistry applied to the arts, in the shape of machines for saving materials and labour, and of processes for attaining the same economy. We have described the effects of some of these manifold inventions in the improvement of the condition both of producers and consumers. But there are many particulars in which knowledge has laboured, and is still labouring, for the advance of the physical and moral condition of us all, which may have escaped attention; because these labours operate remotely and indirectly, though not without the highest ultimate certainty and efficiency, in aiding the great business of production. These are the influences of science upon labour, not so direct as the mechanical skill which has contrived the steam-engine, or so indirect as the operation of ethics upon the manufacture of a piece of woollen cloth; but which confer a certain and in some instances enormous benefit upon production, by the operation of causes which, upon a superficial view, appear to be only matters of laborious but unprofitable speculation. If we succeed in pointing out the extent and importance of those aids which production derives from the labours of men, who have not been ordinarily classed amongst "working men," but who have been truly the hardest and most profitable workers which society has ever possessed, we shall show what an intimate union subsists amongst those classes of society who appear the most separated, and that these men really labour with all others most effectually in the advancement of the great interests of mankind. [Illustration: Harrison.]