Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1884-03-14

should give good definition. show OBJ
jects clearly and well defined, that the
stand be of good material and workman.
ship, that there be no shake or lateral
motion in the adjustments of tho focus,
that the focus be instantly changeable
when desired and that it have Joint for
inclination.
"The simplest of nll simple microscopes
are, of course, the watchmaker's glass the
engraver's glass, the common pocket
glass with from one lens to three lenses,
the achromatic triplets for the watch
guard and the hread-counters. In that
class is the collectors pocket micsoscopo
like this, consisting of Stanhope lcnse
in frame with glass cover, forming n
live box i'll which the object may he
placed. 1t has power of about 20 diam
eters, and is useful on collecting excurs-
ions. Animslculs, diatoms, algp, and
other objects can readily be examined
with it. In the same class are micros-
copes with glass cages for holding seeds,
aud the flower microscope, with forceps
for holding objects. OF microscopes with
stands this is the simplest" taking up n
compact little instrument. "With its
three lenses combined it has power of 33
diameters, which is sufficient to show
many of the larger animalculs in pond OF
ditch water, the scales from butterfly g
wing, pollen grains from plants, aud
thousands Of other objects. 1t packs in
to box that acts as base for the up.
right brass stem. An animalculae cage, q
pair of brass forceps, watch glass, two
plain glass slips, and a prepared object
go with it. 1t sells for 50. 80. This school
microscope is nearly similar, but it works
easier, and is adapted for educational
purposes. This dissecting microscope,
with large, firm stage, you probly dc
not care to look at. OF the compound
microscopes this one, selling for 50. so, is
the simplest. 1t is, as you see, of polish
ed brass, with one eye-piece and one OBJ.
ject glass, magnifying when combined
about 40 diameters, or 1000 times.
"Microscopists understand magnifyinp
power in diameters. Here is powerful
instrument, with hinged Joint for house
hold use. Its two object glasses magnify
from 900 to 10000 times, Beneath the
stage is a concave mirror for the iliumina
ton of Opaque objects. The prices range
from SIS to $40. For an amateur good
instrument can be bought for S23 or $28
which has stage with adjustable spring
clips, a revolving diaphragm of four aper
lures beneath the stage, aud concayt
mirror for use under or above the stage
1t can magnify 5S 600 times, and with the
addition of one-tifth object glass, will
adapter and cap, 10000 DR.. O. w
Holmes, of Boston, designed neat little
microscope for use by classes. 1t is very
simple F.; n common lamp furnishes the il
Elimination. A folding microscope, o
powers ranging from 40 to 40 diamcters
for tourists; can be bought for from SIS t,
800, For students in histology and veg
etable anatomy, we have Instrument
that range in price from $50 to $3.50, anC
when one of the cheapest is furnishe,
with condenser, polariscopc, Gamers
luciln, stage micrometer, spot lens, 200
phyto through, live box, and forccps it i
complete for almost any investigation
The binoculars have e-pieccs that Civ
500 diameters, or magnify 100000 times
This binocular," carefully handling
superb Instrument was made in Eng
land, and suppose it is the most per
feet of all microscopes. 1t has all th
latest improvements in construction, an,
it has every possible adjustment. Til
stage and all the optical arrangement
are carried by the limb, which is sufficient
ly solid to practically abolish vibration
Vibration, by the way, is one of the wors
troubles that microscopic has to ovel
come. In using the highest powers of
superior instrument, the least vibrati 10
will prevent satisfactory examination
G Some microscopists have their instru
ments mounted on tables, resting O
foundations of stone built up throug
t the house, and not allowed to come j
wit, S,,,
you an idea of how fine the adiustmeu
must be. This instrument has con
pound goniometer stage, graduated Oh
silver ring to $50 , with complete rotar
, and rectangular movements, and new eel
: tring adjustments. The sub-stage wit
centring and focusing adjustments, is 7,
. movable by lateral slide for illumin'
. ton by the mirror. Tke instrumen
with two pairs of eye-pieces, three objet
. glasses, condensing lens, stage forcer
% % and hand plyers, packed in lnahogan
. case, costs about 1885,
, "The accessories are almost MS interes
:, ing as the instrument itself The Gamer
u lucida consists of minute 45o prism
" through which the reflected image is see
:, while the paper and the pencil point a
u seen around the prism. The compress
!, is al arrangement lOr tAHlllulnP my hu
J. or yielding object. The mechanical ii
- !, ger is delicate apparatus for arrangl
i diatoms and putting them in any desire
~ ~ position. Other accessories are Adal
:, ers, acromatic amplifers, blue glass slll
: for neutralizing the yellowness Of arti
y cial light, condensers for the illuminate
/, of Opaque objects, eye shades, microm
~ ~ ter gauges, analyzers, polarizers, spectr
40 40 scope eye-piece, sub stage condensers al
e io illuminators, life slides for keeping mi
u ~ ute organisms alive and in n position,
&C. g, observation, paraboloids, and zoophy
oa troughs. A siphon slide in which livi
iie objects can be kept for observation
.;s days or weeks is an interesting apparatl
Ii9 n9 Through n chamber containing the m
lLn ute object current of water passes c.
r nl5 tinuously, and the processes of respi
IN IN ton, circulation, and digestion and
W effects Of poisons can be studied. '