Let us look first at the notions still customary about inventors and inventions which are derived from past circumstances. The popular idea of an inventor is of a man who makes an immense addition to the real wealth of the world—who invents the steam engine, or the spinning jenny, or the Jacquard loom, or the hot blast—almost revolutionising the material powers of mankind. The idea associated with his work is in any case that of great novelty in means coupled with great accomplished results. Now there are various reasons why these should not be the characteristics of modern inventors and inventions, as we see they are not. It might be true that there are still as many inventions of real novelty and magnitude as ever, though we doubt if there is; and yet there would be circumstances which prevented a legislator regarding them as most important. One of these circumstances is certainly the exaggerated importance of minor improvements, in consequence of the great development of machinery and manufacturing. A single improvement to save 10 per cent, in fuel for the steam engine would probably add more absolutely to the real wealth of this generation than the invention of the steam-engine itself added to the real wealth of the generation in which it was invented. A recent invention just spoken of—the feathering of the blades of screws, increasing the facilities of using auxiliary steam-power in ships—might compare on the same footing with the most substantial invention of a poorer age. Just as the refinement of the machinery of credit, and the extent of its development, cause the least disturbance to be widely felt, so the least improvement in mechanical or chemical knowledge, applied to manufactures, may have great results. A revolutionary invention—owing to the difficulty of introduction—might not tell so quickly even as a minor improvement in an existing groove; but, in any case its effects will now be matched at the first start by these minor improvements.