22 
THE YOUNG SCIENTIST. 
counterbalance the weight of the angle 
plate and the work, because it is found 
that unless it is counterbalanced in the 
latter it will be turned oval instead of 
round. This, however, has no effect upon 
radial faces, and hence would not affect 
the pipe bend unless the circumference of 
the flange required to be turned up. 
In Fig. 2 is shown the angle plate em- 
ployed to ensure parallelism of two sur- 
faces. It is shown holding a pillow-block, 
which requires to have its hole bored 
parallel with the bottom surface (shown 
resting on the angle plate). 
The slot and holes shown in the angle 
plate are to enable it to be moved from or 
towards the centre of the lathe face-plate 
to suit the height of the w^ork. The bot- 
tom edge of the angle plate is made curved 
as shown, so as to be able to stand well 
Pond Hunting. 
WHILE there is no doubt that the 
highest pleasure that can be de- 
rived from the microscope, is to be found 
in its successful application to the practi- 
cal problems of science, or of daily life, it 
is also true that the next best thing is the 
examination of fresh, natural objects, 
either from the animal or the vegetable 
kingdom. Compared with living diatoms, 
desmids, or infusoria, the finest mounted 
objects are "as water unto wine." The 
one class may be beautiful, but it is dead 
and imperfect; the other is living with 
all its beauty fresh upon it. We might as 
well compare a fine picture or marble bust 
with a beautiful living woman in all the 
power and character of her womanhood, 
as to compare dead objects with living 
CLOSTEEIUM LUNULA. 
out on the plate without striking the lathe 
bed, as it would do if the corners were left 
square. 
The top surface of the angle plate is 
provided with numerous holes to receive 
bolts to clamp the work, which should be 
held by bolts and plates as shown (and 
not by bolts passing through the angle 
plate and through the work), so as to 
enable setting the work true on the angle 
plate rather than moving the angle plate 
endways or on the face-plate. 
In setting the angle plate for distance 
from the lathe centre, a piece of wood 
should be used, because striking the bare 
metal with a hammer would soon destroy 
the truth of the surfaces. 
— In keeping living microscopic speci- 
mens in small aquaria, the chief points are 
steady temperature, and neither too much 
nor too little light. Too much light kills 
the animals ; too little kills the plants. 
ones. Therefore, v/e would most earnestly 
advise our readers to go pond hunting, if 
they would get the greatest amount of 
enjoyment out of their microscopes. 
Natural objects are not difficult to find. 
They abound in every pool and quiet 
stream. The difftculty is to find out what 
they are after we have got them. Knowing 
and feeling this, we propose to give every 
month one or two illustrations or pictures 
of such common objects as are found 
everywhere. These pictures will be easily 
recognised, and as we shall give the names 
and habits of the objects, our young 
friends will in time form new acquaint- 
ances amongsi their invisible friends, 
which will be pleasant if not profitable. 
In former numbers of the Young Sci- 
entist we have given accounts of the 
Volvox, the For^iceZZa, etc., illustrated with 
figures. In this number we give a de- 
scription of one of the most common and 
beautiful of all the desmids— the Clos- 
