In the same year, Gorham invented the twine-binder for harvesters, Bennett improved the gelatine-bromide process of Maddox; and Locke and Wood invented the self-binding reaper. In 1874, Glidden and Vaughan invented a machine for making barbed wire, and Sir William Thomson invented his super-excellent siphon-recorder for receiving messages over the Atlantic cable. This invention combined the three elements that constitute a great invention; brilliancy of conception, excellence of construction and concrete product. It was of immediate usefulness also, which a great invention may not necessarily be. But Sir William Thomson was a "canny Scot," a good mechanic, and a man of the world, as well as a mathematical physicist of the highest order; with the result that even on his loftiest flights, he held tight to a string that connected him to the earth, and that kept his flights within the regions of the practical and immediate. His siphon-recorder was very much more sensitive to electric currents than any recorder ever invented before; a quality which made feebler currents utilizable, decreased induction and therefore increased speed. Coming when it did, and coming because Sir William Thomson saw a need for it, it was a great and important contribution to submarine telegraphy, and therefore to the Machine; for the Machine has now become very large and complicated, and needed the best possible communication among its various parts. Some of these parts were far distant from each other. In the following year, 1875, Brown invented his cash-carrier. This was not so brilliant or important an invention as Sir William Thomson's; but it can hardly be doubted that a hundred thousand times as many cash-carriers and their children, cash-registers, have been made as siphon-recorders. In the same year, Lowe invented his illuminating water-gas; Wegmann his roller flour mills; Smith his middlings purifier for flour; and Pictet his ice-machine. The last four inventions were of that distinctly practical kind that contribute directly to the operativeness of the Machine, by facilitating the conditions of living in large communities, and make great cities possible. Of the four, the invention of Pictet was the most brilliant and scientific, and the least directly useful. In 1876, Bell made an invention that is usually conceded to be the most important of modern times, and that was also of the highest order of brilliancy of conception, excellence of construction and concreteness of result. The invention was that of the speaking telephone.