How? or, Spare hours made profitable for boys and girls (1887)
Holbrook, Kennedy · New York, Worthington co. · leaf 223
and in themiddle of this fit an upright board a foot wide, which hasa hole cut in its center ten inches in diameter. Fasten it 218 A BOYS SOLAR MICROSCOPE. strongly in place by four nails driven through the frame,and well into the ends of the boards, or, if more conven-ient, by long screws inserted… … Fif of the frame. The upper part of the window must alsobe closed, so that no ray of light shall enter the room,except through the hole d. Before proceeding further, it may be well to remark,that, as perhaps the largest part of the work is the cut-ting of no less than seven circular holes of…
Handicraft · Amusements
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