How to become an inventor : $b Containing experiments in photography, hydraulics, galvanism and electricity, magnetism, heat, and the wonders of the microscopeWarford, Aaron A.
Science
How to become an inventor : $b Containing experiments in photography, hydraulics, galvanism and electricity, magnetism, heat, and the wonders of the microscope
Warford, Aaron A.
Scientific recreations
If the object be transparent, and requires to be seen by transmitted
light, the following plan will answer:--Take a thin piece of wood, cut
or punch a round hole out of the middle, and support it on four legs.
Wires or wooden pegs fixed in corks will answer the purpose well, and
if the corks be glued to the corners of the board, the legs can be
inserted or removed at pleasure. The wood of which cigar-boxes are
made will answer the purpose very well. Its dimensions should be about
three inches in length by two in width. Now buy one of the doll’s
looking-glasses that are sold for a penny, and put it under the stand.
Lay a flat piece of glass over the hole, place the object upon it, and
direct the light through it by means of the mirror below. If such a
mirror cannot be obtained, it is easy enough to make one, by mounting a
piece of looking-glass in a cork frame, and making it swing on pivots,
like the glasses of our dressing-rooms.
The young microscopist must remember that when he is examining
any object by transmitted light, he must arrange it as flatly as
possible on the glass. In many cases, a still neater manipulation
is required--as, for example, when the petals of flowers are under
examination. Thin glass is to be purchased at any optician’s, and if
cut in squares, instead of circles, is very much cheaper, and quite as
useful for all practical purposes. Lay the petal on the glass plate,
place a piece of the thin glass upon it, and press it gently while
examining it. If it still remains thick and dull, put a drop of pure
water on the petal, and replace the thin glass, when the structure will
almost invariably be detected.
Everything depends on the proper management of the object and the
arrangement of the light. Some opaque objects can be seen best by
direct light, and others by transmitted light. If a leaf be examined,
particularly if it be a thick and heavy one, like that of the ivy,
the upper and lower membranes must be stripped apart--a task which is
easily performed by tearing a small slit, and then ripping it smartly
across. A pair of forceps will be required for this and other delicate
work, and may be obtained at a cheap rate. Care must be taken to keep
the points exactly even, and if at any time one of them appears to be
shorter than the other, they should be rubbed on a hone until they are
brought perfectly level.
These should be made of steel; but the young microscopist will find
that a second pair, made of brass, and much rougher in finish, are
invaluable aids as he takes his walks into the country. By their aid
he can pick up minute objects, draw insects out of crevices without
damaging them, and pluck the tiniest flowers without harming their
petals. They can be carried in the waistcoat pocket, and the cost is
sixpence. Any lad who knows how to handle solder can make a pair for
himself in a few minutes.
Public-domain text, read in full here on John Shaqi.
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