This experience taught me that the square inch of surface demanded three hundredweights of force to make a good impression in a few seconds, and almost less than half that weight when I allowed it to act for a whole minute. According to this calculation the entire sheet, which contained about one hundred square inches, would have demanded thirty thousand pounds; and the stone could have withstood this without cracking, had I been able to apply the pressure evenly. But the imperfections of the press made it necessary to apply a pressure three times as great, and this the stones could not bear. To correct the defects of this press was more than I cared about, after I was nearly killed by the three hundredweights, which fell accidentally, and, as I stood immediately under it, would have beaten out my brains had not a miracle caused the load to catch and hold. The thought that a similar accident might cause the death of one of my men made me hate the whole press, all the more so as I had conceived what seemed to me at the time an exceedingly happy idea for a very simple and not costly printing-machine. Before I possessed a press of my own, I used to pull proofs of my work in the following manner, in order to avoid the constant trips to a printer. I laid the dampened paper on the inked stone. Over it I laid some heavy paper, and then a sheet of stiff, carefully smoothed dry paper. Then I took a piece of polished wood and rubbed this over the upper sheet of paper, holding the latter firmly to prevent slipping. I continued the rubbing, using more or less power according to whether I wanted the impressions deep or pale. Thus I obtained impressions very often that could not have been better. I wondered why this could not be done on a large scale, and proceeded to try at once. I stretched a piece of linen firmly over a wooden frame two feet long and wide. On this linen I pasted a sheet of strong paper, polished on the upper side with wax. Then with two bands the frame was fastened to an ordinary wooden table. Then the stone was fastened on the table under the frame. Inside of the printing-frame was a smaller frame with cords, to hold the paper, which had a layer of gray blotting-paper under it. With a piece of polished wood, or a piece of glass such as is used by polishers, I rubbed the upper waxed paper thoroughly, making sure that every spot was touched.