THE YOUNG SCIENTIST. 
10 
workmanship, or whether the lenses are 
worked to true spherical surfaces. If the 
rings from a minute globule appear of an 
irregular wavy outline, as shown by the 
annexed cut (Fig. 22), either approximat- 
ing to a polygon or triangle, it shows that 
one of the surfaces at least that refracts 
Fig. 20. Fig. 21. Fig. 22. 
the rays is of this form. Such workman- 
ship is inexcusable, and those that can- 
not avoid it had better let glass-grinding 
alone. 
Finally, there is an appearance that I 
have sometimes seen in our best object- 
glasses, when focussed away from a 
globule, viz., "Newton's rings;" this 
shows that in the contact surfaces of one 
of the pair of lenses, the convex is deeper 
than the concave, and bears hard in the 
middle. This may have no worse effect 
than loss of light ; but still it is as well 
avoided. 
Gravitation Converted into Home At- 
traction. 
BY A. W. ROBERTS. 
WHAT shall we do to-night, little 
folks ? Tell stories, or make some- 
thing?" 
"Oh make something! make some- 
thing. Papa!" was the general reply. 
"What shall it be?" 
"Makea'grunk man,' what the side- 
walk jumped up and made the bleed 
come, so that he had to sit down till the 
soger man came around and took him 
to his mother." 
We all laughed at little "Dumps" re- 
quest, which I promised to grant. 
" Now, then, bring forth your 'trump- 
ery ' as Mamma calls it, and we will see 
if there is a sufficiency of uselessness to 
construct a drunken man out of." 
Cast aside slate sponges, crooked sticks, 
tissue paper, beeswax, shells of English 
walnuts, some old water colors, a piece of 
lead pipe, two tumble bugs, anda " hoppy 
toad," which Ned informed me he had 
kept for three days hidden under the 
lounge, and I musn't tell Mamma nor 
Bridget. From these, was to come forth 
a terrible example of intemperance. 
For a correct likeness of the drunken 
man the reader is referred to Fig. 1, which 
Fig. 1. 
was made in the following manner : The 
shells of an English walnut were fas- 
tened together with beeswax, after which 
a hole was bored through the smaller end 
to admit of a stick of wood, six inches 
long, and pointed at the end, which was 
then fastened in the hole with hot wax. 
Another piece of wood five inches long, 
the ends of which curved upwards was 
fastened to the first stick, two inches be- 
low the nut, with thread. 
With plaster-of-Paris and a piece of 
lead pipe, I was to cause this forthcom- 
ing man to reel and tumble about, as if 
greatly demoralized. 
Mixing the plaster to a thick paste, I 
placed a layer half an inch thick in -a 
small bowl, well greased with lard to pre- 
