Henry B. H.—Excellent directions for the construction of a cheap telescope are given in Young People No. 1.
Charles Conner.—We can not undertake any such commissions.
J. R. Foster.—Pages of advertisements are almost always given in weekly papers. You will find them in every bound volume of Harper's Weekly, and similar publications.
"North Star."—You understand the art of making puzzles, but you must be more careful with your spelling. There is only one "e" in cathedral.
Albert Mullen.—Box-wood only is used by engravers on wood, as it has a fine grain and the requisite hardness. It can be got out in small pieces only, and these are either glued or screwed together to form large blocks. When a picture is to be engraved in haste, the block is taken apart and the pieces are given to several engravers, in order to save time. Sometimes thirty or more engravers are employed at once on a single block.