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[[half-circled--in upper left corner]] 99 [[/half circled]] former operation: this being done, take the two from between the [[strikethrough]] pieces [[/strikethrough]] pieces of iron, and placing the two outermost of the touching bars in their [[in left margin]] Step -3. [[/in margin]] room, let the other two be the outermost of the four to touch these with: and this process being repeated till each pair of bars have being touched three or four times over, which will give them a considerable magnetic power, put the half dozen together after the manner of the four (Fig. 4.) [[in margin]] Step-4.[[/in margin]]and touch with them two pair of the hard bars, placed between their irons at the distance of about half an inch from each other: then lay the [[in margin]] Step-5.[[/in margin]] soft bars a side; and with the four hard ones let the other two be impregnated (Fig. 5.) holding the touching bars apart at the lower end near two tenths of an inch, to which distance let them be seperated after they are set on the parallel bar, and brought together again before they are taken off: this being observed, proceed according to the method described above, till each pair have been touched two or three times [[in margin]] Step-6.[[/in margin]] over. But as this vertical way of touching a bar will not give it quite so much of the magnetic virtue as it will receive, let each pair be now touched once or twice over, in their parallel position between the irons (Fig.6.) with two of the bars held horizontally, or nearly so, by drawing at the same time the north of one from the middle over the south end, and the south of the other from the middle over the north end of a parallel bar; then bringing them to the middle again without touching the parallel bar, give three or four of these horizontal strokes to each side. The horizontal touch, after the vertical, will make the bars as strong as they can possibly be made: as appears by their not receiving any additional strength, when the vertical touch is given by a greater number of bars, and the horizontal by those of a superior magnet power. This whole process may be gone thro' in about half an hour, and each of the [[in margins]] Strength of these bars.[[/in margins]] large bars, if well hardened^[[(*)]], may be made to lift twenty eight troy ounces, and sometimes more. And when these bars are thus impregnated, they will give to an hard bar of the same size, its full virtue in less than two minutes: and therefore will answer all the purposes of magnetism in navigation and experimental philosophy, much better than the load stone, which is well known not to have sufficient power to impregnate hard bars. The half [[in margins]] how to put them up. [[/in margins]] dozen being put into a case (Fig. 7.) in such a manner, as that two poles of the same denomination may not be together, and their irons with them as one bar, they will retain the virtue they have received: but if their power should, by making experiments, be ever so far impaired, it may be restored without any foreign assistance in a few minutes. And if, out of curiosity, a much larger set of bars should be required, these will communicate to them a sufficient power to proceed with, and they may in a short time, by the same method, be brought to their full strength.
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[[in margins]] To harden Iron. [[/in margins]]
(*) The smith's manner of hardening steel, whom I have chiefly employed, and whose bars have constantly proved better than any I could meet with beside, is as follows: having cut a sufficient quantity of the leather of old shoes into very small pieces, he provides an iron pan, a little exceeding the length of a bar, wide enough to lay two side by side without touching each other or the pan, and at least an inch deep. This pan he nearly [[strikethrough]] fills [[/strikethrough]] half-fills with the bits of leather, upon which he lays the two bars, having fastened to the end of each a small wire to take them out by