Perkins, Henry, 1803-1889, publisher, Haswell, Barrington, and Haswell, printer, McManus-Young Collection (Library of Congress) DLC · Philadelphia : H. Perkins, 134 Chestnut Street · leaf 46
moreperfect if the red-hot iron be concealed from the eye of thespectator : this may be done by placing upon the iron a piece ofblackened tin, with a hole cut out, the size of the coin to be heated. TO MAKE A PRISM. Provide two small pieces of window-glass and a lump of wax;Soften and mould the… … show the angle, a9 at which thepieces of glass meet; into whichangle put a drop of water. To use the instrument thus made,make a small hole, or a narrowhorizontal slit, so that you can see the sky through it, when youstand at some distance from it in the room. Or a piece of paste-board placed in…
Scientific recreations
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