File:The book of stars; being a simple explanation of the stars and their uses to boy life, written to conform to the tests of the Boy scouts (1915) (14591941118).jpg

Identifier: bookofstarsbeing00coll (find matches)
Title: The book of stars; being a simple explanation of the stars and their uses to boy life, written to conform to the tests of the Boy scouts
Year: 1915 (1910s)
Authors: Collins, A. Frederick (Archie Frederick), 1869-
Subjects: Astronomy Stars
Publisher: New York, D. Appleton and company
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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he stick which has the mirror fastened I ? Fig. 42.—Top View of Heliograph. to it into the slotted end of the baseboard, push the bolt throughthe holes and after slipping on the washer put on the thnmbscrew. The mirror can now be moved to and fro. Into the hole in the front part of the base put a wire or a 7 Fig. 43.—Side View op Heliograph. thin round stick to sight the mirror by. The heliograph is nowready for use. After sighting the mirror at the place where the signalsare to be received, set the mirror so that the reflected beam ofsunlight shines directly on the place. To send signals in the. 42 THE BOOK OF THE STARS Morse code all you need to do to make dots and dashes is toplace a sheet of cardboard before the mirror and take it away;the length of time the mirror remains uncovered determineswhether it is a dot or a dash. The heliograph complete isshown in Fig. 44. How to Make a Simple Sundial.—To make a sundial ofthe usual kind that will give the correct Sun time is not an
Text Appearing After Image:
Fig. 44.—Heliograph Complete. easy matter, for the spaces marking the hours on the dial arenot equal as they are on the face of the clock and this will makeit hard to figure out. A kind of sundial that will give the correct Sun time though,can be easily made and at little cost. Get a strip of tin 2inches wide and 24 inches long; mark it off into 24 equal spaceslike those on a two-foot rule, and beginning at one end with the THE SUN, BRIGHTEST OF ALL STARS 43 number 1, number each space to 24, as shown in Fig. 45. Thisdone, bend the strip of tin into a perfect ring with the numbersinside and solder the joint, as shown in Fig. 46. Next get a strip of iron or brass % mcn wide, yi6 inchthick and 13 inches long; drill a 1/16 inch hole through each I IT W BT YU WW. K XXI HI 211XIX XX HI MMMIX2K zv Fig. 45.—Numbered Strip for Sundial. end and a %-inch hole 4 inches from one end; bend this stripinto an exact semi-circle, as shown in Fig. 47 and solder thetin ring, at the point where numbe

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