Although the older cement manufacturers predicted utter failure, they have since recognized the success of Edison's long kiln, and it is now being used quite generally in the trade. Another invention of minor nature but worthy of note relates to the weighing of the proportions of cement-rock and limestone. In most cases the measurement is usually by barrow loads, but Edison determined that it must be done accurately to the pound, and devised a means of doing it automatically, for, as he remarked, "The man at the scales might get to thinking of the other fellow's best girl, so fifty or a hundred pounds of rock, more or less, wouldn't make much difference to him." With Edison's device the scales are set at certain weights and the materials are fed from hoppers. The moment the scale-beam tips an electrical connection automatically stops the feed and no more can be put on the scale until the load is withdrawn. Another and important new feature introduced by Edison was in raising the standard of fine grinding of cement ten points above the regular standard of seventy-five per cent, through a two-hundred-mesh screen. By reason of the great improvement he had made in grinding machinery he could grind cement so that eighty-five per cent, passed through a two-hundred-mesh screen. As cement is valuable in proportion to its fineness, it will be seen that he has thus made an advance of great importance to the trade. We cannot enter into all the details of the numerous inventions and improvements that Edison has introduced into his cement plant during the last eight or nine years. It is sufficient to say that by his persistent and energetic labors during that period he has raised his plant from the position of a newcomer to the rank of the fifth largest producer of cement in this country. A remarkable instance of the power of Edison's memory may be related here. Some years ago, when the cement plant was nearly finished and getting ready to start, he went up to look it over and see what needed to be done. On the arrival of the train at ten-forty in the morning he went to the mill, and, starting at one end, went through the plant to the other end, examining every detail. He made no notes or memoranda, but the examination required all day. In the afternoon, at five-thirty, he took a train for home, and on arriving there a few hours later got out some note-books and began to write from memory the things needing change or attention. He continued on this work all night and right along until the next afternoon, when he completed a list of nearly six hundred items. This memory "stunt" was the more remarkable because many of the items included all the figures of new dimensions he had decided upon for some of the machinery in the plant.