Washed Emery Graded by Settling Time, and Emery Paper, Cloth and Sticks (Tomlinson, 1854)

"Mr. Chezy prepared very fine emery for optical purposes in the following manner."

Grind coarse emery well on an iron plate with an iron muller (break lumps first in a mortar).

Put it in a vessel rather wider at the bottom than the top, fill with clear water to 8 or 10 in above the emery, stir hard with an iron spatula and let it settle an hour. Put the short branch of a syphon 4 in below the surface and draw the turbid water into another vessel without disturbing the first; refill, stir and repeat until the water runs clear. (That first powder is too fine for grinding glass.) Repeat with the remaining emery, drawing off after half an hour: the deposit in the second vessel is 'emery of half-an-hour'; then a quarter of an hour, and so on down to half or a quarter of a minute. Dry each grade.

Brush paper over with thin glue and dust the emery over it from a sieve; there are about six degrees, sieves of 30 and 90 meshes per linear inch giving the coarsest and finest. Emery-cloth is the same on thin cotton cloth instead of paper (it lasts longer in the hand, though it does not wrap a file so readily).

Plane deal rods 8 to 12 in long, square or with one side rounded, drive a nail into each end as handles, brush with thin glue, dab all over in a heap of emery and knock on one end to shake off the excess. Give two coats.

From Charles Tomlinson (ed.), **Cyclopaedia of Useful Arts** (1854), vol. I, "Emery" (checked on the archive.org scan cyclopaediaofuse01tomluoft, p. 595). The tools and the diagram are ours.