208 EQUATORIAL STAR FINDER FOR BEGINNERS. 
circumstances, I very much felt the need of something to assist in 
searching, and for confirmation of my observations. After some 
consideration, I designed and made the finder you now see. The 
circles are made from old clock dials roughly divided by hand 
(cardboard would do quite well). The right ascension circle is 
divided to minutes, the dec. to degrees. The finder requires 
to be placed on a level stand (I used a large flower vase). 
It must stand when in use in its proper position in regard to the 
meridian of the place. To do this, find the longitude of the place 
on a map, and for every degree that it is west of Greenwich it will 
be 4 minutes later than Greenwich time ; for every degree that it 
is east it will be 4 minutes earlier. This will give the time of the 
place when this is found. Stick a piece of wire upright on the top 
of the stand, and at the correct time of noon draw a line along the 
shadow made by the wire and the sun; this line will be the guide 
for placing the finder. To find the polar axis, take a piece of 
wood or cardboard, say, 14 by 18 inches, stand it with its 14-inch 
end on the top of the stand or table. Look along its edge, and 
tilt it until the edge comes in a line with the pole star; this will 
give the required angle. To use, place the finder in its proper 
position as to north and south on the stand, guided by the line 
already drawn, and I will assume that the top star (Delta) in the 
belt of Orion is known to the observer. Look for its position in 
the star map, which will be found to be: R.A., 5 hrs. 26 mins. ; 
Dec., 0 deg. 23 mins. S. Look through the tube, and _ bring 
the star into the centre, turn the R.A. and Dec. circles until the 
pointers are on these figures. Now, suppose you want to find 
Castor in Gemini: Find its position on the star map, which is 
R.A. 7 hrs. 27 mins., Dec. 32 deg. 9 mins. N. Without touching 
the circles, turn the Dec. and polar axis until the pointers are 
on these figures, and the tube will be pointing to the star, or 
very near it. Now, suppose you see a star or group of stars in 
the sky, and you wish to know what this particular star is, or in 
what constellation the group is. Again adjust the R.A. circle on 
Delta (Orion) or any other star the position of which is known; 
turn the tube to the star or group, and the pointers will give the 
R.A. and Dec. ; find this place on the star map, and this will show 
what the star or group is, and in what constellation it is situated. 
It is not to be expected from this roughly-made and imperfectly- 
divided finder that its readings will be quite accurate, but it cer- 
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