The influence of the magneto-electric machine, therefore was not direct, but indirect. It was a basic invention; and like many basic inventions, it formed the hidden foundation on which a conspicuous superstructure was later to be reared. One of the lessons of history is that it is the men and the methods and the other things which are in evidence when some important occurrence happens, that are identified with it in the minds of people not only at the time, but afterward. An invention that may have cost its creator the toil and struggle of a lifetime may not gain success simply because of some existing unfavorable conditions of some kind. Suddenly the conditions become favorable. John Doe takes advantage of all the work that other men have done, adds some slight improvement, achieves "success" and dons the laurel wreath. We see at this time (1832) very clear signs of an increasing number of inventions per year, an increasing speed of invention. We see an acceleration in invention which we cannot help associating in our minds with the acceleration which any material object gets, when continuously subjected to a uniform force, like that of gravity. One almost feels that there must be a continuous force impelling men to invent; so clear is the increase of the speed of inventing. Following the magneto-machine in 1832 came the invention of a rotary electric motor by Sturgeon, the discovery of chloral-hydrate by Liebig, the production of the first large American locomotive by Baldwin and the invention of link motion by Sir Henry James. The last was an exceedingly important and ingenious contribution to the steam engine, especially in locomotives and ships; for it gave a very quick and sure means of reversing its direction of motion, and of regulating the travel of the valve and the degree of expansion of the steam. In the following year came Stephenson's steam whistle; and in the year following (1834) came the McCormick reaper. Few inventions have had a greater or a more immediate effect on the trend of modern progress, which is to influence men to live in large communities. For the McCormick reaper could do so much more work, and so much better work, than men could do without it, that the cultivation of extensive areas of land could be undertaken with the assurance that large crops of grain could be secured. This not only secured more grain for the country, but liberated many men from toil on farms, and permitted them to migrate to the cities.