THE YOUNG SCIENTIST. 
61 
April 17— lOh. 20m. evening. 
" 20— 7h. 10m. evening. 
>S^ Ca^CBI— Minimum — April 19, lOh. 57m. 
eve. This star has a period of 9.48 days, and 
changes from the 8th to 10.5th mag. To ena.ble 
the amateur to find it we will give its place : 
Eight ascension, 8h. 36m.; declination, 19° 30' N. 
Delta LiBEA.— Period 2d, 7h. 51.0m.; E. A., 
14h. 53m. ; dec, 7° 58' S. Near the right foot of 
the Virgin. Changes from 4.5 to 6 magnitude. 
Minima: 
April 3— 5h. 44m. morning. 
" 7— 9li. 26m. evening. 
« 10— 5h. 17m. morning. 
" 15— 9h. Om. evening. 
" 17— 4h. 51m. morning. 
" 21— 8h. 33m. evening. 
" 24 — 4h. 25m. morning. 
" 28— 8h. 7m. evening. 
smooth board, and rub the wood over it. This- 
is the best method for all small articles. For 
general purposes, however, it is best to make a 
sand-board, which is done in this way : Cut two 
pieces of smooth pine, three-eighths of an inch 
thick, three inches wide and four long ; through 
one of them put three slender screws in a line 
and one and one-half inches apart, long enough 
when the heads are driven in flush with the 
wood to have the points pro.) ect about one-fourth 
inch on the other side. File these points sharp, 
and make corresponding holes in the other 
block. Now cut a piece of sandpaper four inches 
wide and seven and one-half long, and lay one 
end upon the screw points, pressing them 
through the paper. Then stretch the paper 
tightly around the block, and fasten the other 
end upon the points. Lay upon this the other 
block, and fasten the two together with a screw 
LONG 
Bate. 
Star's Name. 
Pliase. 
April 4. 
S Ophiuchi. 
maximum. 
" 7. 
R Cygni. 
maximum. 
" 8. 
i^Tauri. 
maximum. 
" 14. 
T Herculis. 
minimum. 
" 15. 
R Aquilao. 
maximum. 
" 19. 
ZJYirginis. 
minimum. 
" 19. 
R Vulpeculac. 
minimum. 
" 20. 
R Andromedae. 
maximum. 
" 20. 
R Yirginis. 
minimum. 
" 22. 
R Sagittae. 
minimum. 
" 30. ■ 
R Leonis. 
minimum. 
Period in 
nmnge of 
B. A. 
Declination. 
Bays. 
Magnitude. 
16h. 26m. 
16° 53' south. 
229 
3.3 to 13.5 
19h. 33m. 
49° 54' north. 
416 
8 to 14 
4h. 21m. 
9° 52' north. 
327 
8 to 13 
18h. 4m. 
31° 0' north. 
160 
7.9 to 13 
19li. Om. 
8° 2' north. 
352 
0.5 to(?) 
12h. 44m. 
6° 16' north. 
212 
7.5 to 12 
20h. 59m. 
23° 18' north. 
147 
8 to 13.5 
Oh. 17m. 
47° 51' north. 
0 to(?) 
12h. 32m. 
7° 43' north. 
146 
G.5 to 11 
20h. 8m. 
16° 20' north. 
70.88 
8.3 to lo.a 
Oh. 41m. 
12° 2' north. 
312.57 
5 to 11.5 
U CoEONAE.— E. A., 15h. 13m. ; dec. 31° 51' N. 
Minima : 
April 8— Ih. 35m. morning. 
" 14— llh. 17m. evening. ^ 
" 21— 8h. 59m. " 
Penn Yan, N. Y. 
Use of Sandpaper. 
It would seem as if sandpapering were one of 
the easiest and simplest matters, and yet there 
are few things connected with this art that are 
so little understood. The ordinary way with 
the novice is to tear off a piece of sandpaper, 
hold it with his Angers, and rub the wood with 
it. This method is very likely to lead to bad 
results. If it is a piece of open work that needs 
smoothing, the paper takes off too much wood 
at the edges, and rounds them off. Or, if it is a 
flat piece of wood, the fingers bear on harder in 
some places than others, and make the surface 
uneven. 
Now, there are two ways to sandpaper nicely. 
If the piece of work is small, fasten a whole 
sheet of sandpaper to your bench or a flat. 
at each end. A pair of common screw-eyes that 
are used for hanging picture frames will be use- 
ful for this purpose. It would be well to have 
two sets of these blocks made to hold coarse 
and fine sandpaper. Now lay the work upon 
the bench, hold it with one hand, and rub 
with the sand-board, carefully and l^riskly, and 
with a circular motion. If the wood is at all 
rough, begin with No. 1 sandpaper, and finish 
with No. 00. Before using the paper on any 
fine work, examine it carefully, and pick out 
any large pieces of sand which might score the 
wood. 
If the amateur is fortunate enough to possess 
a turning lathe, he will find that the following 
contrivance will save him a great deal of labor : 
Make (or have them made by some turner) sev- 
eral cylinders of wood, four inches long and 
three and one-half in diameter. Stretch around 
one of these a half sheet of sandpaper, and glue 
the two ends to the wood. Set this in the lathe, 
revolve rapidly, and it will smooth the wood 
very quickly. The writer uses half a dozen of 
these cylinders, with a different number of sand- 
paper on each. — Arthur Hope. 
