x^Svffli

Boston Medical Library
in the Francis A.Countway
Library of Medicine ^Boston

Illustrated Price List

MICROSCOPES,

Microscopic Apparatus

AND OTHER

Optical Instruments,

MANUFACTURED FY

R. & J. BECK,

LONDON.

" Vino Bono Non Opus Est Hedera."

AMERICAN BRANCH;

No. 1016 CHESTNUT STREET,

PHILADELPHIA.
W. H. WALMSLEY, Manager.

THE FOLLOWING MEDALS

HAVE BEEN AWARDED TO

R. & J. BECK,

FOR THE

" Excellence of their Microscopes ; and the Cheapness of their

Manufacture:"

The Council Medal of The Great Exhibition of
1851.

The First-Class Medal of The French Exhibition
,oe 1855.

The Prtze Medal of The International Exhibition

oe 1862.

The Gold Medal of The Second French Exhibition
of 1867.

The Medal and Diploma of The American Centen-
nial Exhibition of 1876.

"The Gold Medal of The Ninth Cincinnati Exposi-
tion of 1881.

WE DID HOT EXHIBIT AT PARIS IN 1878,

PREFACE.

The reputation enjoyed by the Microscopes and other Optical Instru-
ments manufactured by us is world-wide, and has been maintained for
more than a quarter of a century against all competition. This reputa-
tion was first gained, and was maintained during many years, through the
production of First-Class instruments ; perfection without regard to cost
having been our aim. Of late years the Microscope having been greatly
popularized, there has arisen a demand for cheap instruments, and a
demand that has been mainly filled by literally worthless articles of
French manufacture, made to look well and to sell, but as instruments of
precision or research utterly useless. Believing that a discriminating pub-
lic would sustain us in an effort to produce a thoroughly well-made and
reliable Microscope for a low price, we some years since introduced our
Economic and National Stands and Accessories, and the result has fully
established the correctness of our anticipations. Their sale has been
simply enormous among professional men and students, in medical and
other colleges, to various departments of the Government, and to families
and amateurs all over the country. This has been due to their perfect
construction, mechanically and optically, and to their cheapness; no other
instruments in the market at all approaching them in these particulars.
The same exacting care that is bestowed upon the construction of our
most costly stands and accessories is given also to these cheaper ones, and
the result is seen in the production of instruments that really have no
rivals.

A demand having arisen of late for Stands, with Swinging Sub-Stages,
and Broad-Gauge Screws, in addition to the usual Society Standard, we
have fully met the same by the introduction of our '• Ideal," and Improved
National Microscopes, which will be found illustrated and described in
these pages.

The details of the Optical Instruments manufactured by us having
extended the size of this Catalogue to the largest convenient limits, we
feel obliged to issue a Second Part (now in course of preparation), which
will be devoted to the illustration and description of our Standard
Meteorological Instruments, Thermometers, Barometers, Anemometers, Rain
Gauges, Compasses, Hygrometers, etc., etc.

Thanking our friends for the liberal manner in which our efforts to

furnish first-class instruments at moderate prices have been encouraged by

them, we are

Yours truly,

January 1, 1882. R. & J. BECK.

R. & J. BECK, PHILADELPHIA.

No. 33. One-third Actual Size.

"The International" Improved Large Best Microscope Stand.

R. & J. BECK, PHILADELPHIA. 5

DESCRIPTION of the IMPROVED
LARGE BEST OR "INTERNATIONAL" MICROSCOPE STAND.

The Improved Large Best or u International " Microscope Stand has a
tripod (A) for its base, upon which is placed a revolving fitting (B), graduated
to degrees, by which means the Microscope can be turned around without its
being lifted from the table, and the amount of such rotation registered ; upon
this fitting two pillars are firmly fixed, and between them the limb (C) can be
elevated or depressed to any angle, and tightened in its position by the lever (D).
The limb carries at one end the body (E) (Binocular or Monocular), with Eye-
pieces and Object-glasses; in its centre the Compound Stage (F), beneath which
is the circular plate, sliding on a dove-tailed fitting, and moved up and down by
the lever (Z), and carrying the supplementary body or Sub-stage (G) ; and at the
lower end a triangular bar carrying the Mirror (H). Each of these parts requires
a separate description. .

THE BINOCULAR BODY.

The Binocular body consists of two tubes, the one fitted in the optical axis of
the Microscope, and the other oblique. At their lower end and immediately
above the object-glass there is an opening, into which a small brass box or fitting
(I) slides; this box holds a prism so constructed that when slid in it intercepts
half the rays from the object-glass, diverts them from their direct course, and
reflects them into the additional or oblique tube. To the prism- box is attached
a spring-catch, which, when pressed in, permits of the removal of the prism-
box; but this is only needed for cleaning, as, when the box is drawn back to the
distance allowed by this spring, the prism in no way interferes Avith the field of
view, and all the rays pass up the direct body, and the Microscope is converted
into a Monocular one.

The upper or eye-piece ends of the tubes are fitted with racks and pinion for
varying the distances between the two eye-pieces, to suit the differences between
the eyes of various persons ; and arrangements are made for racking out one
tube more than the other, to suit irregularities or inequalities between the eyes
of the observer.

This body is moved up and down with a quick movement by means of the
milled heads (K), and with a very delicate and fine adjustment by the milled
head (L). This milled head works against a lever, which moves a slide inde-
pendent of the rack-movement, and gives an adjustment at once certain and
decided.

THE STAGE.

The Compound Stage is of an entirely new construction: the object is most
frequently merely placed upon it, but, if necessary, it can be clamped by care-
fully bringing down the spring-piece (M) ; the ledge will slide up or down, and
the object may be pushed sideways; this arrangement forms the coarse adjust-
ment. Finer movements in vertical and horizontal directions are effected by
means of two milled heads (N and O), the screws attached to which are kept up
to their work by opposing springs, so as to avoid all strain or loss of time. The
whole stage revolves in a circular ring by the milled head (P), or this can be
drawn out, and then it turns rapidly by merely applying the fingers to the two
ivory studs (Q,, Q,) fastened on the top plate, which is divided into degrees to
register the amount of revolution. The Stage is attached to the limb on a pivot,
and can be rotated to any angle, which angle is recorded on the divided plate
(R), or can be turned completely over, so that the object can be viewed by light
of any obliquity without any interference from the thickness of the stage.

Beneath and attached to the stage is an iris diaphragm (S), which can be alto-
gether removed, as shown in the illustration, from its dove-tailed fitting, so as

6 R. & J. BECK, PHILADELPHIA.

not to interfere during the rotation of the stage. The variations in the aperture
of this diaphragm are made by a pinion working into a racked arc and adjusted
by the milled head (T).

THE APPARATUS BARS.

Beneath the stage are two triangular bars (U, V), the one revolving around and
the other rigid in the optical axis of the instrument. On the former the sub-
stage (G), carrying all the apparatus hereafter described for illumination and
polarization, fits, and is racked up and down by the milled head (W); the mir-
ror also, if desired, slides on the same bar; the revolving motion to this bar is
given by the milled head (X), and the amount of angular movement is recorded
on the circle (Y), whilst the whole of this part of the stand is raised and lowered
concentric with the optical axis of the instrument by the lever (Z), and the
amount of such elevation or depression registered on a scale attached to the
limb. This bar can be carried around and above the stage, and be thus used for
opaque illumination.

The lower triangular bar (V) carries the mirror H, or a right-angle prism, when
the illumination is required to be concentric with the optical axis of the instru-
ment, and independent of the movements of other illuminating apparatus.

THE MIRROR.

The mirror-box contains two mirrors, one flat and the other concave ; it
swings in a rotating semicircle attached to a lengthening bar, which enables it
to be turned from one side to the other, and revolves on a circular fitting for
giving greater facilities in regulating the direction of the beam of light reflected,
the whole sliding on either of the triangular bars, previously referred to, and made
to reverse in the socket (a) so as to bring the centre of the mirror concentric
with the axis of the Microscope in either case.

THE SWINGING SUB-STAGE.

As the mirror alone is insufficient for many kinds of illumination, some pro-
vision has to be made for holding various pieces of apparatus between the object
and the mirror. For this purpose a supplementary body, or sub-stage, is
mounted perfectly true with the body, and is moved up and down in its fitting
by rack and pinion connected with the milled heads (W). This sub-stage, to
which reference has already been made, is now regarded as one of the most
important parts of the Achromatic Microscope; in it all the varied appliances
for modifying the character and direction of the light are fitted. But a lew years
since it was considered sufficient for this part of the stand to be constructed so
as to move up and down perfectly coincident with the optical axis of the instru-
ment, and for that purpose it was racked in a groove planed out on the same
limb as that on the upper end of which the optical portions were carried. But
lately microscopists have shown the desirability of affording every facility for
lateral angular adjustments; and this has led to the sub-stage being attached to
an arc (6) working in the circular plate (Y), and moved by a rack and pinion
(X), whilst the amount of such angular movement is recorded on the upper
surface of the plate (Y). Having once fixed the angular direction of the light,
the focusing of it depends upon the lever (Z), which moves the circle up and
down, and with it the arm carrying the illuminating apparatus, in the optical
axis of the instrument. So long ago as 1854 Mr. Grubb, of Dublin, called attention
to the advantage of mounting the illuminating apparatus on a revolving arm
or arc, which he thus describes in his provisional specification for improvements
in Microscopes, No. 1477, 5th July, 1854: — "My third improvement consists in
the addition of a graduated sectorial arc to microscope, concentric to the plane
of the object Hn situ,' on which either the aforesaid prism or other suitable illu-
minator is made to slide, thereby producing every kind of illumination required
for microscopic examination, and also the means of registering or applying any
definite angle of illumination at pleasure," With but slight modification, this
is the plan adopted in this Stand.

E. & J. BECK, PHILADELPHIA.

FIRST-CLASS MICROSCOPES.

In these Microscopes the Stands, the Object-glasses, the Illuminating, and all
Accessory apparatus, are carried to the highest possible perfection.

PRICE $1650.

No. l. Improved Large best Binocular Microscope, " The International,"
with Swinging Sub-stage, and New Arrangements for Rotating
and Revolving the Concentric Rotating Stage with Iris Diaphragm,
and also for adjusting and Rotating the Illuminating Apparatus, with
all the latest additions complete.

12 Object-glasses, magnifying from 8 to 10,000 linear : 4 in. (8°), 3 in. (12°), \\ in.
(23°), f in. (32°), & in. (55°), ^ in. (90°), I in. (75°), * in. (100°), J in. (120°), A in.
immer. (160°), & in. (140°), ^ in. (140°).

Lieberkuhns to the following Object-glasses : 1|, No. 89, f , No. 90, ^, No. 91,
i, No. 92.

10 Eye-pieces, viz., 1 pair No. 1, 1 pair No. 2, 1 pair No. 3, 1 No. 4, 1 No. 5, No.
97, 1 pair Reiner' s Eye-pieces, No. 96. Indicators to 6 Eye-pieces, No. 152.
Graduated Draw-tube, No. 100. Erecting-glass, No. 99, for use with the f Object-
glass for erecting the Image and varying the power from 5 to 150 linear. Achro-
matic Condenser, with revolving Diaphragm, No. 101. Patent Achromatic Con-
denser, No. 101*. Right-angle Prism, No. 104. Adapter for centering illuminating
apparatus, No. 94. Brown's Iris Diaphragm, No. 113. Amici's Prism, No. 105.
Nachet's Prism, No. 107. Wenham's Parabolic Reflector, No. 108. Spot-lens, No.
110. Rainey's Moderator, No. 135. White-cloud Illuminator, No. 127. Polarizing
Apparatus, No. 116. Darker's Series of Selenites, No. 117. Sorby's Micro-
Spectroscope, No. 63. Sorby's Standard Spectrum-scale, No. 67*. Sorby's
Dichroiscope, No. 67. Leeson's Goniometer, No. 154. Tourmaline, No. 125.
Two Double-image Prisms, and Selenite Film, and Brass Plate with holes, No.
123. Set of 6 Crystals, showing rings round the optic axis, No. 124. Large Bull's-
eye Condensing-Lens, No. 130. Smaller Side Condenser, No. 131. Side Silver
Reflector, No. 133. Parabolic Illuminator with Sorby's Reflector, No. 129.
Beck's Patent Illuminator, No. 126. Three Dark Wells and Holder, No. 136.
Opaque Disk Revolver, No. 138. Quadruple Nosepiece in Aluminium, No. 161.
Wollaston's Camera Lucida, No. 155. Neutral-Tint-Glass Camera, No. 156.
Eyepiece Micrometer, No. 146. Stage Micrometer No. 147. Set of Live-Traps,
No. 173. Lever Compressor, No. 162. Wenham's Compressor, No. 165. Paral-
lel-plate Compressor, No. 163. Reversible Compressor, No. 164. Screw Live-
Box, No. 166. Large Live-Box, No. 167. Small Live-Box No. 168. Growing-
Cell, No. 172. Two Large Troughs, No. 169. Two Glass Plates with Ledge and
Covers, No. 171. Set of Three Glass Fishing-Tubes, No. 180. Maltwood's
Finder, No. 150. Frog-plate, N. 175. Mineral-holder, No. 145. Three-pronged
Forceps, No. 143. Tightening-Key, No. 181. Stage Forceps, No. 144. Brass
Pliers, No. 145*.

The whole packed in an Upright Spanish Mahogany Case, with two boxes

containing the Apparatus.

3 R. & J. BECK, PHILADELPHIA.

PRICE $1100.

No. 2. Improved Large Best Binocular Microscope, " The International,"
with Swinging Sub-stage, and New Arrangements for Rotating
and Revolving the Concentric Rotating Stage with Iris Diaphragm,
and also for Adjusting and Rotating the Illuminating Apparatus,
with the following accessories :

9 Object-glasses, magnifying from 12 to 5000 linear :— 3 in. (12°), 1| in. (23°),
§ in. (32°), & in. (90°), \ in. (75°), \ in. (100°), \ in. (120°), & in. immer. (160°),
& in. (140°).

Lieberkuhns to the following Object-glasses :—l|, No. 89, f, No. 90, ^j, No. 91,
£, No. 92.

7 Eyepieces, viz. 1 pair No. 1, 1 pair No. 2, 1 pair No. 3, 1 No. 4, No. 97.
Indicators to 4 Eyepieces, No. 152. Graduated Draw-tube, No. 100. Erecting-
Glass, No. 99, for use with the § Object-glass, for erecting the Image and varying
the power from 5 to 150 linear. Achromatic Condenser, with revolving Dia-
phragm, No. 101. Right-angle Prism, No. 104. Plain Diaphragm. Amici's Prism,
No. 105. Nachet's Prism, No. 107. Wenham's Parabolic Reflector, No. 108.
Spot-Lens, No. 110. Polarizing Apparatus, No. 116. Darker' s Series of Selenites,
No. 117, Two Double-image Prisms and Selenite Film, and Brass Plate with
holes, No. 123. Large Bull's-eye Condensing- Lens, No. 130. Smaller Side Con-
denser, No. 131. Parabolic Illuminator, No. 128. Three Dark Wells and Holder,
No. 136. Opaque Disk Revolver, No. 138. Quadruple Nosepiece in Aluminium,
No. 161. Wollaston's Camera Lucida, No. 155. Eyepiece Micrometer, No. 146.
Stage Micrometer, No. 147. Lever Compressor, No. 162. Wenham's Compressor,
No. 165. Parallel-plate Compressor, No. 163. Screw Live-Box, No. 166. Large
Live-Box, No. 167. Small Live-Box, No. 168. Large Glass Trough, No. 169. Two
Glass Plates with Ledge and Covers, No. 171. Set of Three Glass Fishing-Tubes,
No. 180. Maltwood's Finder, No. 150. Frog-plate, No. 175. Mineral-holder,
No. 145. Tightening-key, No. 181. Stage Forceps, No. 144. Brass Pliers, No.
145*

The whole packed in an Upright Spanish Mahogany Case, with two boxes

containing the Apparatus.

PRICE $725.

No. 4. Improved Large Best Binocular Microscope, " The International/'
with Swinging Sub-stage, and New Arrangements for Rotating
and Revolving the Concentric Rotating Stage with Iris Diaphragm,
and also for Adjusting and Rotating the Illuminating Apparatus,
with the following accessories :

5 Object-glasses, magnifying from 30 to 1300 linear:— 1£ in. (23°), § in. (32°), fi.
In. (55°), £ in. (100°), | in. (120°).

Lieberkuhns to the following Object-glasses : — f , No. 90, ^, No. 91.

6 Eyepieces, viz. 1 pair No. 1, 1 pair No. 2, 1 pair No. 3, No. 97. Indicators
to 2 Eyepieces, No. 152. Graduated Draw-tube, No. 100. Erecting-Glass, No. 99,
for use with the § Object-glass, for erecting the Image and varying the power
from 5 to 150 linear. Achromatic Condenser, with revolving Diaphragm, No. 101.
Plain Diaphragm. Wenham's Parabolic Reflector, No. 108. Polarizing Appa-
ratus, No. 116. One Selenite. Large Bull's-eye Condensing-Lens, No. 130.
Smaller Side Condenser. No. 131. Parabolic Illuminator, No. 128. Three Dark

K. & J. BECK, PHILADELPHIA. 9

Wells and Holder, No. 136. Opaque Disk Revolver, No. 138. Double Nose-
piece, No. 159. Wollaston's Camera Lucida, No. 155. Eyepiece Micrometer,
No. 146. Stage Micrometer, No. 147. Wenham's Compressor, No. 165. Par-
allel-plate Compressor, No. 163. Large Live-Box, No. 167. Small Live-Box,
No. 168. Large Glass Trough, No. 169. Two Glass Plates with Ledge and
Covers, No. 171. Set of Three Glass Fishing Tubes, No. 180. Maltwood's Finder,
No. 150. Mineral-holder, No. 145. Tightening-Key, No. 181. Stage Forceps,
No. 144. Brass Pliers, No. 145*.

The whole packed in an Upright Spanish Mahogany Case, with one box

containing the Apparatus.

PRICE $600.

No. 6. New Large Besi Binocular Microscope, with Concentric Rotating
Stage, Centering and Rotating Sub-Stage and Iris Diaphragm, with

the following Apparatus.

4 Object-glasses, magnifying from 30 to 700 linear:— 1| in. (23°), f in. (32°), "^
in. (55°), £ in. (100°).

Lieberkuhns to the following Object-glasses :— |, No. 90, ^, No. 91.

6 Eyepieces, viz. 1 pair No. 1, 1 pair No. 2, 1 pair No. 3, No. 97. Indicator
to 1 Eyepiece, No. 152. Graduated Draw -tube, No. 100. Erecting-Glass, No. 99,
for use with the § Object-glass, for erecting the Image and varying the power
from 5 to 150 linear. Achromatic Condenser, with revolving Diaphragm,
No. 101. Plain Diaphragm. Wenham's Parabolic Reflector, No. 108. Polariz-
ing Apparatus, No. 116. One Selenite. Large Bull's-eye Condensing-Lens, No.
130. Smaller Side Condenser, No. 131. Parabolic Illuminator, No. 128. Three
Dark Wells and Holder, No. 136. Double Nosepiece, No. 159. Wollaston's Ca-
mera Lucida, No. 155. Eyepiece Micrometer, No. 146. Stage Micrometer, No.
147. Wenham's Compressor, No. 165. Large Live-Box, No. 167. Small Live-
Box, No. 168. Large Glass Trough, No. 169. Two Glass Plates with Ledge and
Covers, No. 171. Set of Three Glass Fishing-Tubes, No. 180. Maltwood's Fin-
der, No. 150. Mineral-holder, No. 145. Tightening-Key, No. 181. Stage Forceps,
No. 144. Brass Pliers, No. 145*.

The whole packed in an Upright Spanish Mahogany Case, with one box

containing the Apparatus.

PRICE $550.

No. 7. New Large Best Monocular Microscope, with Concentric Rotating
Stage, Centering and Rotating Sub-Stage and Iris Diaphragm.

With the same Object-glasses and Apparatus as No. 6.

PRICE $450.
No. 8. New Large Best Binocular Microscope, with Concentric Rotating
Stage, Centering and Rotating Sub-Stage and Iris Diaphragm, with
the following Apparatus.

3 Object-glasses, magnifying from 30 to 700 linear:— 1\ in. (23°), § in. (32°), £
in. (85°).

Tlie Cases for any of the first-class stands may be brass-bound and all blocks screwed in. This will add
from 87.50 to $25.00 to the expense, according to the amount of apparatus.

10

K. & J. BECK, PHILADELPHIA.

Mode of Packing First-class Microscopes and Apparatus.

E. & J. BECK, PHILADELPHIA.

11

Mode of Packing First-class Accessories.

Mode of Packing First-class Accessories.

12 R. & J. BECK, PHILADELPHIA.

Lieberkuhn to the | Object-glass, No. 90.

0 Eyepieces, viz. 1 pair No. 1, 1 pair No. 2, 1 pair No. 3, No. 97. Indicator
to 1 Eyepiece, No. 152. Graduated Draw-tube, No. 100. Erecting-Glass, No. 99,
for use with the $ Object-glass, for erecting the Image and varying the power
from 5 to 150 linear. Achromatic Condenser, No. 102. Polarizing Apparatus, No.
115. One Selenite. Large Bull's-eye Condensing-Lens, No. 130. Smaller
Side Condenser, No. 131. Parabolic Illuminator, No. 128. Three Dark Wells
and Holder, No. 136. Large Live-Box, No. 167. Two Glass Plates with
Ledge and Covers, No. 171. Tightening-Key, No. 181. Stage Forceps, No.
144. Brass Pliers, No. 145*.

The whole packed in an Upright Honduras Mahogany Case, with one box

containing the Apparatus.

PRICE $400.

No. 9. New Large Best Monocular Microscope, with Centering and Rotating
Stage, Centering and Rotating Sub-Stage.

With the same Object-glasses and Apparatus as No. 8.

PRICE $337.50.
No. 10. New Large Best Binocular Microscope, with Concentric Rotating
Stage, Centering and Rotating Sub-Stage and Iris Diaphragm, with
the following Apparatus.

2 Object-glasses, magnifying from 60 to 400 linear:— fin. (32°), £ in. (85°).

4 Eyepieces, viz. 1 pair No. 1, 1 pair No. 2, No. 97. Indicator to 1 Eyepiece,
No. 152. Graduated Draw-tube, No. 100. Smaller Side Condenser, No. 131.
Large Live-Box, No. 167. Two Glass Plates with Ledge and Covers, No. 171.
Tightening-Key, No. 181. Stage Forceps, No. 144. Brass Pliers, No. 145*.

The whole packed in an Upright Honduras Mahogany Case, with one box

containing the Apparatus.

PRICE $300.

No. ii. New Large Best Monocular Microscope, with Centering and Rotating
Stage, Centering and Rotating Sub-Stage.

With the same Object-glasses and Apparatus as No. 10.

PRICE $650.

No. 12. New Small Best Binocular Microscope, with Concentric Rotating
Stage and Centering Sub-Stage.

5 Object-glasses, magnifying from 20 to 1300 linear :—l§ in. (23°), § in. (32°), &
in. (55°), £ in. (100°), £ in. (120°).

Lieberkuhns to the following Object-glasses : — § No. 90, ^ No. 91.

6 Eyepieces, viz. 1 pair No. 1, 1 pair No. 2, 1 pair No. 3, No. 98. Indicators to
2 Eyepieces, No. 152. Graduated Draw-tube, No. 100. Erecting-Glass, No. 99,
for use with the § Object-glass, for erecting the Image and varying the po iver
from 5 to 150 linear. Achromatic Condenser, with revolving Diaphragm, No.
101. Wenham's Parabolic Reflector, No. 108. Polarizing Apparatus, No. 116.
One Selenite. Large Bull's-eye Condensing-Lens, No. 130. Smaller Side Con-
denser, No. 131. Parabolic Illuminator, No. 128. Three Dark Weils and Holder,

R. & J. BECK, PHILADELPHIA. 13

No. 136. Opaque Disk Revolver, 1 tray of disks, No. 137. Double Nosepiece,
No. 159. Wollaston's Camera Lucida, No. 155. Eyepiece Micrometer, No. 146.
Stage Micrometer, No. 147. Wenham's Compressor, No. 165, Parallel-plate
Compressor, No. 163. Large Live-Box, No. 167. Small Live-Box, No. 168.
Large Glass Trough, No. 169. Two Glass Plates with Ledge and Covers, No.
171. Set of Three Glass Fishing-Tubes, No. 180. Maltwood's Finder, No. 150.
Stage Forceps, No. 144. Brass Pliers, No. 145*.

The whole packed in a Strong Fiat Spanish-Mahogany Case.

PRICE $600.

No. 13. New Small Best Monocular Microscope, with Concentric Rotating
Stage and Centering Sub-Stage.

With the same Object-glasses and Apparatus as No. 12.

PRICE $530.

No. 14. New Small Best Binocular Microscope, with Concentric Rotating
Stage and Centering Sub-Stage.

4 Object-glasses, magnifying from 20 to 720 linear;— 1| in. (23°), § in. (32°), ^
In. (55°), £ in. (100°).

Lieberkuhns to the following Object-glasses'— f, No. 90, $y, No. 91.

6 Eyepieces, viz. 1 pair No. 1, 1 pair No. 2, 1 pair No. 3, No, 98. Graduated
Draw-tube, No. 100. Erecting-Glass, No. 99, for use with the § Object-glass, for
erecting the Image and varying the power from 5 to 150 linear. Achromatic
Condenser, No. 102. Wenham's Parabolic Reflector, No. 108. Polarizing Ap-
paratus, No. 115. One Selenite. Large Bull's-eye Condensing- Lens, No. 130.
Smaller Side Condenser, No. 131. Parabolic Illuminator, No. 128. Three Dark
Wells and Holder, No. 136. Double Nosepiece, No. 159. Wollaston's Camera
Lucida, No. 155. Eyepiece Micrometer, No. 146. Stage Micrometer, No. 147.
Wenham's Compressor, No. 165. Small Live-Box, No. 168. Large Glass Trough,
No. 169. Two Glass Plates, with Ledge and Covers No. 171. Sot of Three Glass
Fishing-Tubes, No. 180. Maltwood's Finder, No. 150. Stage Forceps, No. 144.
Brass Pliers, No. 145*.

The whole packed in a Strong Flat Spanish Mahogany Case.

PRICE $337.50.

No. 16. New Small Best Binocular Microscope, with Concentric Rotating
Stage and Centering Sub-Stage.

2 Object-Glasses, magnifying from 60 to 720 linear:— § in. (32°), £ in. (85°).
Lieberkuhn to the § Object-glass, No. 90.

5 Eyepieces, viz. 1 pair No. 1, 1 "pair No. 2, 1 No. 3, No. 98. Graduated
Draw tube, No. 100. Erecting-Glass, No. 99, for use with the § Object-glass, for
erecting the Image and varying the power from 5 to 150 linear. Smaller Side
Condenser, No. 131. Three Dark Wells and Holder, No. 136. Parabolic Illumi-
nator, No. 128. Small Live-box, No. 168. Two Glass Plates, with Ledge and
Covers, No. 171. Stage Forceps, No. 144. Brass Pliers, No. 145*.

The whole packed in a Strong Flat Spanish-Mahogany Case.

Any of the small best stands and apparatus may be had packed in upright Mahogany Case, with bide
case for the accessories, at an additional cost of five dollars.

14 R. & J. BECK, PHILADELPHIA.

PRICES OF FIRST-CLASS
MICEOSCOPE STANDS AND CASES,

IF ORDERED SEPARATELY.

FIRST-CLASS MICROSCOPE STANDS.

No. Price.

33. Improved Large Best Binocular Microscope Stand, "The Interna-
tional," with Swinging Sub-stage, and new arrangements for
rotating and revolving the Concentric Rotating Stage with Iris
Diaphragm, and also for adjusting and rotating the Illuminating
Apparatus. Two pairs of Eye-pieces, Graduated Draw Tube, Pliers,
Forceps, etc., §325 00

34. Improved Large Best Monocular Microscope Stand, " The Interna-
tional," with Swinging Sub-stage, and new arrangements for rotating
and revolving the Concentric Rotating Stage, with Iris Diaphragm,
and also for adjusting and rotating the Illuminating Apparatus.

Two Eye-pieces, Graduated Draw Tube, Pliers, Forceps, etc., . . 275 00

36. New Large Best Binocular Microscope Stand, with Concentric Rota-
ting Stage and Iris Diaphragm, Rotating and Centering Sub-stage,
most complete movements to the Body, Stage, and Double Mirror.

Two pairs of Eye-pieces, Pliers, Forceps, etc., mounted on two pillars, 250 00

37. New Large Best Monocular Microscope Stand, with Concentric Rota-
ting Stage and Iris Diaphragm, Rotating and Centering Sub-stage,
most complete movements to the Body, Stage, and Double Mirror.

Two Eye-pieces, Pliers, Forceps, etc., mounted on two pillars, . . 200 00

44. New smaller Binocular Microscope Stand, on the same principle, and
with the same actions as No. 36, Two pairs of Eye-pieces, Pliers, For-
ceps, etc., but with single pillar, 200 00

45. New smaller Monocular Microscope Stand, on the same principle,
and with the same actions as No. 37, Two Eye-pieces, Pliers, Forceps,

etc., but with single pillar, 150 00

CASES FOR FIRST-CLASS MICROSCOPES.

46. Best Upright Case, in Spanish Mahogany, for Nos. 33 to 37, with best

brass handle, two boxes for Apparatus, 37 50

47. Best Upright Case, in Spanish Mahogany, for Nos. 33 to 37, with best

brass handle, only one box for Apparatus, 30 00

48. Upright Case, in Honduras Mahogany, for Nos. 33 to 37, with best

brass handle, two boxes for Apparatus, 25 00

49. Upright Case, in Honduras Mahogany, for Nos. 33 to 37,. with best
brass handle, one box for Apparatus, 20 00

54. Best Upright Case, in Spanish Mahogany, for Nos. 44 and 45, with

best brass handle and box for Apparatus, 27 50

55. Upright Case, in Honduras Mahogany, for Nos. 44 and 45, with best

brass handle and box for Apparatus, 20 00

56. Strong Flat Case, in Spanish Mahogany, with covered Dovetails, for

Nos. 44 and 45, with best brass handle, , , . , , , , 16 00

K. & J. BECK, PHILADELPHIA.

15

No. 36. One-third Actual Size.

Large Best Binocular Microscope Stand.

16

B. & J. BECK, PHILADELPHIA.

No. 44. One-third Actual Size.

New Small Best Binocular Microscope Stand.

E. & J. BECK, PHILADELPHIA. 1 7

PRICES OF ACHROMATIC OBJECT-GLASSES AND APPARATUS FOR
FIRST-CLASS MICROSCOPE STANDS.

ACHROMATIC OBJECT-GLASSES.

No.

70
71
72
73
74
75
76
77
78
79
80
81
82
83
84

Focal length.

4 inches
3 inches
2 inches
1]4 inches
% inch
T4D inch
T4ff inch
% inch
£inch
4 inch

i^inch

fs inch
iminer.

5xff inch

3^ inch

iminer.

inch

Linear magnify' g pow'r
nearly, with eyepieces

Draw-tube closed..
Ditto if drawn out, add

for each inch

Draw-tube -dosed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out add

for each inch

Draw-tube closed

Ditto if drawn out. add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Dra w-tube closed

Ditto if drawn out, add

for each inch

Draw-tube closed

Ditto if drawn out, add

for each inch

Draw -tube closed..
Ditto if drawn out, add

for each inch

Draw-tube closed..
Ditto if drawn out, add
for each inch

No. 1.

No. 2.

No. 3.

No. 4.

No. 5.

10

16

26

32

52

n

12

3

20

5

40

6

48

8
74

2

20

4

38

6

70

7

85

10
130

4

30

6

56

8
100

12
120

15
190

5

7o

7
120

12
220

15
270

22
410

8
120

14
210

25

370

27
460

48
710

14
146

24
255

34
460

46
560

70
890

18
200

32
340

48
590

60
720

80
1120

24
225

42

400

63
700

85
860

120
1450

18
225

35

400

60
700

80
860

130
1450

18
400

35

680

60
1180

80
1440

130

2240

50
500

85
870

140

1500

180
1850

280
2800

60
900

100
1570

180

2750

190

3450

370

4950

80
900

150
1570

300
2750

350
3450

900
4950

80
1800

150
3140

300

5500

350
6900

900
9900

160

360

600

700

1800

Angle of

aperture;

about.

9

12

18

23

32

55

90

75

85

100

120

160

140

170

140

Price.

85. | inch, Homogeneous Oil Immersion,
about 1.32, (

Four Systems. Numerical aperture

8 c.
15 00

29 00

29 00

29 00

26 00

42 50

60 00

42 50

42 50

52 50

69 00

50 00

125 00

117 50

170 00

LIEBERKUHNS FOR OBJECT-GLASSES.

£75 00

No.

Object-
glass.

Price.

No.

Obj ect-
glass.

Price.

No.

Object-
glass.

Price.

87.
88.

3-inch,
2-inch,

$ c.
5 75
5 75

89.
90.

lj-inch,
f-inch,

$ c.
5 75
4 20

91.
92.

To-inch,
£-mch,

$ c.
4 00
4 00

i

18 R. & J. BECK, PHILADELPHIA.

APPARATUS.

No. Price.

65. Sorby's New Micro-Spectroscope, adapted to the Binocular Micro-

scope, §45 00

66. Sorby's Spectroscope Eye-piece, for the Microscope, in Mahogany

Case. (See " Popular Science Review," No. 18), . . . 50 00

67. Sorby's Dichroiscope, 9 00

67*. Sorby's Standard Spectrum -scale, 9 00

68. Cells, for use with Sorby's Spectroscope, 6 sizes, assorted, per

dozen, ..." 4 00

94. Adapter for centering or throwing out of centre, and for revolving
the Illuminating Apparatus ; applicable only to " The International

Stands," 25 00

96. Orthoscopic Eye-pieces, giving a very large field, each, . . . 9 00

97. Eye-pieoes for the Improved Large Microscope, each, . . . 7 50

98. Eye-pieces for the Improved Smaller Microscope, each, . . . 6 75

99. Erecting-glass, 8 00

100. Draw-tube for First-class Microscopes, 4 75

101. Achromatic Condenser, with Revolving Diaphragm, with stops,

aperture from 25° to 80°, complete adjustments, . . . . 42 50
101*. Patent Achromatic Condenser, with Rotating front, with five
Lenses for varying the magnifying power and angle of aperture,
central rays stopped out by grinding off the back of two of the Front

Lenses, ' 45 00

102. Achromatic Condenser, without Diaphragm, aperture from 20° to

60°, complete adjustments, 22 50

103. Brass Work of Achromatic Condenser, 8 50

103*. Set of Two Patches and one Central Stop, for Achromatic Con-
denser, 3 50

104. Right-angle Prism, for reflecting the light more perfectly than the

Flat Mirror, . . 22 50

104a. Right-angle Prism, as applied to " The International," . . . 25 00

104*. Achromatic Right-angle Prism, as Condenser instead of Mirror, . 27 50

105. Amici's Prism, for oblique light, for the First-class Stands only, . 17 50

106. Amici's Prism, on Separate Stand, 17 50

107. Nachet's Prism, for oblique light, 9 00

108. Wenham's Parabolic Reflector, for the First-class Stands, . . 15 00
109* Achromatic Amplifier ; fitted to any stand ...... 15 00

110. Spot Lens, mounted in brass fitting, . . " 4 50

111. Equilateral Prism on Stand, for oblique illumination, . . . 9 00

112. Adapter on Stand, for use of Object-glass as Condenser, . . . 5 00

113. Brown's Iris Diaphragm, 17 50

115. Polarizing Apparatus, with 1 Film of Selenite, 22 00

116. Polarizing Apparatus, with extra-large Polarizing Prism, . . 35 00

117. Darker's Series of Selenites, adapted for the First-class Stands only, 33 00

118. Selenite Film, of two colors, 2 25

119. Selenite Stage, Red and Green or Blue and Orange, each, . . . 3 25

120. Darker's Selenite Stage, giving 13 tints, 18 50

121. Black Glass, for Polarizing Light, 4 50

122. Bundle of Glass, for Polarizing Light, 9 00

123. Two Double-image Prisms and Selenite Film, with fittings to Eye-

piece, and brass plate with holes, * . 18 50

123*. Single Double-Image Prism, in fitting, 8 00

124. Crystals to show rings round the Optic Axis, each, from, . . . 4 50

125. Tourmalines, each, from, 8 00

126. Beck's Patent Illuminator, in a brass box, for viewing Objects as

Opaque under high powers, 4 50

126*. Beck's Patent Illuminator, with Smith's Diaphragm, . . . 6 00

127. White-cloud Illuminator, . . . 4 50

128. Parabolic Illuminator, fitted to the li-inch and f -inch Object-glasses, 9 00
128*. Parabolic Illuminator with fittings adjusting it to any Object-glass, 10 00

129. Parabolic Illuminator, same as No. 128, with the addition of Sorby's

Reflector, 18 00

130. Large Bull's-eye Condensing Lens, on Stand, 9 00

130*. Large Bull's-eye Condensing Lens, on Stand, with Lamp at-
tached, -. . • 13 50

R, & J. BECK, PHILADELPHIA. 19

No. Price.

131. Smaller Condensing Lens, with Fitting to Limb of the First-class

Stands, $3 00

132. Smaller Condensing Lens, on Stand, 6 00

133. Side Silver Reflector, with Fittings to Limb of the First-class Stands, 9 00

134. Side Silver Reflector, on Stand, 9 00

135. Rainev's Light Moderator, on Stand, . 9 00

136. Three~Dark Wells and Holder, . . . . . . . 5 00

137. Opaque Disk Revolver, one Tray of Disks in case, . . . 15 00

138. Opaque Disk Revolver, with 3 Trays of Disks, Forceps, Capsule of

Gold Size, in Mahogany Case, complete, . 25 00

139. Opaque-Disk Revolver, and Forceps, 9 00

140. Boxes containing 24 Disks, . 4 50

141. Trays containing 24 Disks, .... .... 4 50

142. Three-pronged Forceps, in German Silver, with Screw Adjustment, 7 50

143. Three-pronged Forceps, ' . . . 6 00

144. Stage Forceps, 3 50

144*. Paper-pointed Forceps, 50

145. Stage Mineral-holder, 9 00

145*. Best Brass Forceps, .......... 3 25

146. Eye-piece Micrometer, with Jackson's Adjusting Screw, . . . 8 50

147. Stage Micrometer, mounted in brass, 4 50

148. Stage Micrometer, mounted in card, 2 25

149. Stage Micrometer, mounted in brass, parts of English Inch and

Millimetre, 6 00

149*. Stage Micrometer, mounted in card, parts of English Inch and

Millimetre, 4 00

150. Maltwood's Finder, in Case, 3 50

152. Indicator to each Eye-piece, 2 25

153. Shade to each Eye-piece, 3 50

154. Leeson's Goniometer, . . . . . . . . . . 22 00

155. Wollaston's Camera Lucida, with Lens to magnify Pencil Point, . 8 75

156. Neutral-tint Glass Camera Lucida, 3 25

157. Steel Disk Camera Lucida, ......... 6 50

158. Brook's Double Nose-piece, in Aluminium, curved, . . . . 25 00

159. Brook's Double Nose-piece, curved, . . . . . . 12 50

159*. Triple Nose-piece, curved, 17 50

160. Quadruple Nose-piece, curved, 30 00

161. Quadruple Nose-piece, curved, in Aluminium, 42 50

162. Lever Compressorium, 8 50

163. Parallel Compressor, 9 00

164. Reversible Compressor, 9 00

165. Wenham's Compressorium, for use with Wenham's Parabola, . 3 50

166. Screw Live-box, 6 50

167. Large Live-box, 3 75

168. Smaller Live-box, 3 00

169. Large Glass Trough, with Wedge and Spring complete, . . . 3 75

170. Smaller Glass Trough, with Wedge and Spring complete, . . 3 00

171. Glass Slip, with Ledge, 40

172. Growing-cell, for preserving objects alive in water for many days, 4 50

173. Set of Six Live-traps and Trough, in Case, complete, . . . 12 50

174. Live-trap, 3 25

175. Frog-plate, with Bag, etc, complete, 4 50

176. Glass Slip, with Hollow and Ledge, 50

177. Glass Slip, with Hollow, and Ledge, and Lip, . ... . . l 50

178. Glass Slip, with Hollow, 15

180. Glass Tubes, Set of Three, 50

181. Key for Tightening Joint of First-class Instruments, . . . 2 25

182. Opal Glass, for Moderating the Light, 3x1 inch, .... 40

183. Blue Glass, for Moderating the Light, 3x1 inch, .... 40
186. Astral Oil Lamp, Flat Wick and Shade, with arrangement for

varying height of flame above the table, 6 50

186*. Case for Lamp, No. 186, and 1 chimney, . . . . . . 4 00

188. Gas Lamp, Argand Burner, Shade and six feet of flexible tubing,

with arrangements for varying height of flame above the table, . 13 50

189. Fiddian's Microscope Illuminator, in Case, 15 00

190. Lamp Chimneys, for Nos. 186 or 188, 20

191. Weber's Slip, with Convex Cell, 75

20

IJ. & J. BECK, PHILADELPHIA.

MICROSCOPIC ACCESSORIES.

No. 73.

No. 81.

Nos. 87-90.

Nos. 91-92. No. 99.

Nos. 96-98.

No. 101.

No. 103*.

No. 101*.

No. 102.

No. 104 a.

No. 100.

E. & J. BECK, PHILADELPHIA.

21

No. 104.

M 105.

No. 127.

No. 152.

No. 153.

22

R & J. BECK, PHILADELPHIA.

No. 107.

No. 94.

No. 110.

No. 109.

No. Ill

No. 112.

E. & J. BECK, PHILADELPHIA.

23

No. 115-116.

No. 117.

No. 154.

No. 118.

No. 119.

No. 116.
Extra large Prism.

No. 122,

No. 120.

No. 121.

24

R. & J. BECK, PHILADELPHIA.

126.

128.

R. & J. BECK, PHILADELPHIA.

25

No. 181.

No. 130.

No. 132.

No. 180.

26

E. & J. BECK, PHILADELPHIA.

No. 139.

No. 136.

No. 141.

No. 131.

No. 144*.

1111111! IlflPll

."- '—-^ip7l£doT7PS^~

No. 150.

No. 133.

No. 134.

P. & J. BECK, PHILADELPHIA.

27

No. 144.

No. 142.

No. 145.

No. 148.

No. 157.

No. 158, 159.

No. 159*.

No. 135.

No. 160-161.

28

K. & J. BECK, PHILADELPHIA.

No. 162.

No. 164.

No. 166.

No. 165.

No. 163.

No. 168.

No. 167.

No. 169.

wZE-JfE^.

No. 170.

No. 175.

R. & J. BECK, PHILADELPHIA.

29

174

30

R. & J. BECK, PHILADELPHIA.

No. 171.

No. 177.

No. 178.

No. 188.

No. 191.

No. 186.

Ne. 130*.

No. 189.

No. 145*.

R. & J. BECK, PHILADELPHIA. 31

ILLUSTRATED DESCRIPTION

OF THE

MICRO-SPKCTROSCOPE,

AS MANUFACTURED HY

13. <3C T. BECl

In giving a description of the forms of Spectroscope as applied to the Micro-
scope, we cannot do better than quote the following introductory explanation,
written by H. C. Sorby, F, R. S. :

" Spectrum Analysis as applied to the Microscope must not be confounded
with that branch of the subject which has yielded such admirable results in the
hands of Bunsen, Kirchhoff, and other physicists. In that method of analysis
it is the number and position of the narrow bright lines or bands into which
the light of the incandescent body is divided by the Spectroscope that enable
the experimenter to identify each different substance. It is, in fact, the analysis
of the emitted light ; whereas in Spectrum Analysis applied to the Microscope it
is the analysis of light which has been modified by transmission through the
substance under examination, and it is the absence and not the presence of
particular rays which makes the spectra characteristic of different subjects. In
this respect it is more analogous to Spectrum Analysis as employed in studying
the chemical nature of the atmosphere of the Sun or stars, as illustrated by the
researches of Kirchhoff, Miiller and Huggins, but the principles involved are
materially different. The absorption-bands in such cases are narrow, sharply
defined lines, characteristic of absorption by gases ; whereas those which play
such an important part in researches with the Spectrum Microscope are usually
broad, gradually shaded off on each side, and only in a few cases so narrow and
sharply defined as to vie with some of the broader dark lines in the Solar
spectrum."

The Micro-Spectroscope, ISTo. 66, (figs. 1 and 2) consists of a series of prisms, A,
arranged for direct vision, fitted into an Eye-piece, and supplied with various
appliances — namely, a slit, B, a supplementary spectrum arrangement, C, con-
sisting of a small right-angle prism, D, a stage, E, for placing an object upon,
and a mirror, F, for reflecting the light and all the necessary adjustments.

In the focus of the top lens, G, of an Eye-piece especially constructed is
placed what is technically termed a slit, B ; this consists of two shutters meeting
in the centre of the field, the one sliding up to the centre of the field of view, and
the other adjusting by means of a delicate milled head, H. Upon the delicacy
of the edge of this slit the value of the Spectroscope largely depends, any irregu-
larity or piece of dust appearing as a dark band at right angles to the spectrum,
under examination, and greatly interfering with the definition.

In the same part of the Instrument is inserted a small right-angle prism, D,
which can be pushed forward or drawn back out of the field of view by the
milled head, I. In the former position it reflects the rays passing through any
object placed, upon the supplementary stage, E, to the eye placed at the eye-end
of the Instrument, K, and enables the observer to compare two spectra with one
another, or to measure and record the position of the absorption-bands, as will
be described hereafter.

Placed on the flat surface of the Eye-piece are a couple of levers, L, moving
two shutters, placed immediately over the slit, for regulating the length of the
spectrum under examination.

Above the top lens, G, of the Eye-piece the most important portion of the
Instrument slides; this consists of a series of prisms, A, so arranged as to give a
direct-vision spectrum, and upon the amount of the dispersion of which prisms,
much of the value of the Instrument depends.

At the side of the main tube is a supplementary stage, E, upon which a stand-
ard scale, to be described hereafter, or a second object is placed, supplied with a

32

E. & J. BECK, PHILADELPHIA.

mirror, F, for reflecting the light through the object, the rays then being totally
reflected by the right-angle prism, D, before alluded to, and thrown up the tube
to the observer.

Fiar. 1.

K Fig. 2.

No. 66.

No. 66.

Directions for Using the Micro-Spectroscope.

Remove the ordinary Eye-piece of the Microscope, and slide the Spectroscope
Eye-piece (Figs. 1 and 2) into the body in its place. Remove the upper tube, M,
containing the series of prisms, and draw back the sliding slit by the milled
head, H, so that one-half of the field of view is clear. Focus the microscope to
the object to be examined, which is placed upon the stage, pass it up to the edge
of the slit, move the side shutters by the levers, L, so as to shut off all side light,
save that passing through the object, and push back the sliding side of the slit
by the milled head, H. Focus the top lens of the Eye-piece to the slit by means

No. 67*.

of the rack-and-pir.ion, N, place the tube, M, containing the compound prism, A»
over the Eye-piece, remove the object from the stage, adjust the slit by means of
the adjusting milled head, H, so as to obtain clear vision, if by daylight, so that
the Fraunhofer lines are faintly seen, replace the object to be examined upon
the stage, and the absorption-bands will be readily seen.

The character of these bands and their position varies in every object ; and
if any practical use is to be made of the investigation, it is necessary not only to

B. & J. BECK, PHILADELPHIA.

33

observe, but to record their position. This is done by means of a Standard
scale (fig. 3) ; the precise mode of attaining this result is described in full in the
description of the Binocular Spectroscope.

The Standard scale, No. 67*, (fig. 3) used with the Micro-Spectroscope
described above consists of two small Nicol's prisms having a plate of quartz
.043 inch in thickness between them ; it is placed when in use upon the supple-
mentary stage, E, and held in its place by the two clips ; the light is thrown in
by the mirror, F, and the right-angle prism, D, reflects the image of the quartz-
bands up to the eye-end, K.

Description of the Binocular Spectroscope.

Whilst the Instrument already described is that which is most ordinarily in
use, Mr. Sorby has planned another form (Sorby's Binocular Spectroscope, No.
65, figs. 4, 5), which can be used with the Binocular Microscope and which for

Fig. 4.A

Fig. 5.A

No/ 65.

No.J65.

many purposes is superior to that already described and gives a larger dispersion.

It consists of the following parts :
1st. An object-glass, A, specially arranged, screwing into the tube of the

Microscope by the outside screw, B.
2d. A series of compound dense glass prisms, C, fitting immediately over

the Object-glass, A.
3d. A tube, D, moving up and down upon that holding the prisms by means

of rack and pinion, E, and carrying the following :

(a) A cylindrical lens, F, for lengthening out the spectrum.
(6) A small right-angle prism, G, sliding in and out of the field of view,
which, when slid in, projects over half the field and throws an image of the
dark bands in a piece of quartz polarized by means of two Herapathites or
flakes of Iodide of Disulphate of Quinine, and termed (c) The Standard
Scale, H. This portion of the apparatus is used when the observer desires
to record the position of the absorption-bands. The plate of quartz which it
contains is cut parallel to the optic axis,* of such a thickness that the
line I) in the Solar Spectrum comes between the third and fourth band. It
is thus described by Mr. Sorby: — "In order to measure the exact position
of absorption -bands, etc., seen in spectra, I have contrived a small apparatus
which gives an interference-spectrum divided by black bands into 12 parts
all of equal optical value. It is composed of two Nicol's prisms, or Hera-
pathites, with an intervening plate of quartz about .043 inch thick, cut
parallel to the principal axis of the crystal, the thickness being so adjusted
that the sodium or D line is exactly 3J, counting the hands from the red end
towards the blue."

*It is a well-known fact that a plate of quartz cut parallel to the optic axis will, under
polarized light, g^ve a series of black bands, the distance between such bands being due to
the thickness of the plate of quartz.

34

E. & J. BECK, PHILADELPHIA.

4th. A small lens, I, to condense the light from the object. And oth. A very
accurate slit, K, one side of which is adjusted by means' ol the delicate milled
head, L.

Mode of Use.

Screw the Object-glass, A, inti the body of the microscope ; slide the rest o
the apparatus on to the object-glass, and turn the latter portion round so that the
sides of the spectrum are seen square or upright, thus | j, not thus

D

Adjust the outer tube by means of the rack-and-pinion movement, E, so that
a clear imago of the slit, K, is visible, regulate the width of the slit by the small
milled head, L, so that if by daylight the more prominent lines in the Solar
Spectrum are seen.

Focus the Avhole body of the Microscope so that the small lens, I, just touches
the object to be examined. Note.— The small lens merely receives the light
from the object and does not form an image of it.

If it is desired to register the position of the absorption-bands under view,
push in the little prism, G, at the side, turn down the small box, H, containing
the Standard Scale, and throw the light through it. In the field of the micro-
scope will be seen on the upper .half the spectrum of the object under observation,
and on the under half an image of the standard scale as under (fig. 6).

Fig. 6.

The above illustration shows the appearance in the field of view when one
half of the held is occupied by the Standard scale and the other by the object
under investigation.

If the small Right-angle Prism, G-, should require to be cleaned, it must be
withdrawn carefully or steadily, to avoid chipping it. The carrier is made with
a projecting prong on one side, which to a groat extent protects the prism ; but
such protection cannot be put on the other side without stopping the light.

A piece of black paper has to be cemented on the back of the small prism, G,
to stop the passage of any direct light. This can be turned up when the prism
requires cleaning, which should be done with a delicate ]3iece of wash-leather or
cambric handkerchief.

If the cylindrical lens, F, is removed for cleaning, care must be taken in re-
placing it that the cell is screwed up so that the two marks on the lens are
parallel with the slit, otherwise the definition will be impaired.

Fluids to be examined under the spectroscope may be placed in tubes and
sealed up ; but it is frequently desirable to have the means of selecting a certain
depth of fluid for this purpose. Tubes are therefore used of different depths,
No. 68, (figs. 7 and 8). Wedge-shaped cells (fig. 9) cemented on glass are also

Fig. 7.

Fis;. S.

Fig. 9.

No. 68.

No. 68.

supplied, into which the fluid may be placed and a thin covering-glass placed on
the top, so as to vary the thickness or depth of the fluid under view.

R. & J. BECK, PHILADELPHIA. 35

THE "IDEAL" MICROSCOPE.

The general design of the new "Ideal" stand is that of our well-known
"Economic" with such alterations and additions as the requirements of the
most advanced workers demand. The instrument is wholly of brass, of the
best workmanship and finish, fifteen inches in height, with the standard length
of tube ; the latter being telescopic, the stand may be shortened to eleven inches,
a most convenient height when the instrument is used in the upright position.
The base is a broad, heavy and perfectly steady tripod, from which rises a stout
column to which the body is hinged so as to allow of its being inclined to any
angle, with a stop at the. horizontal position. The body is of the full standard
size, using the same eye-pieces as those furnished with the " National " stands,
and furnished with an adapter whereby objectives with either the society-screw
maybe used, or those with the new broad gauge or " Butterfield " screw, at
will. The coarse adjustment of focus is made by a rack and pinion of exquisite
smoothness, with sufficient length to permit the focusing of a four-inch objec-
tive. The fine adjustment is by a very delicate spring movement, controlled by
a large milled-head at the rear of the body, most conveniently placed for the
hand. The stage-ring or platform is made of very thin but stiff brass, with a
large, central opening, and is provided with removable and reversible spring
clips, exceedingly delicate, and adapted to any thickness of slide. By these a
slide may be clamped on either the upper or the lower side of the stage and
manipulated with the greatest ease, permitting the employment of the utmost
obliquity of illumination. In addition to this stage-ring or platform, two
movable stages are made, either of which is furnished, as desired by purchasers.
In the first and cheaper form, a circular stage-plate of thin sheet-brass is pro-
vided, which revolves concentrically upon the stage-plate ; in the second, a
glass-stage with stop for a Maltwood finder, and movements of over one inch in
all directions ; and this is the one delineated in the illustration, which shows
this glass-stage removed. The double mirror and sub-stage are attached to a
stout triangular bar, which swings above the upper stage on either side, upon a
graduated circle with a centering stop in the optic axis.

Both mirror and sub-stage slide upon this bar to any position required, or they
can be entirely removed and employed separately or combined, as may bo
desired. The sub-stage ring is of the standard size, carrying any of the usual
accessories, such as paraboloid, polariscope, achromatic condenser, dark- well
and Woodward's prism, and is so arranged that the polariscope and achromatic
condenser may be used in combination, thus greatly increasing the brilliancy
of the former. The mirror swinging above the stage may be used as an illu-
minator for opaque objects, but a condensing lens for this purpose is also pro-
vided. Both the circular and the glass-stages are fitted for carrying a pair of
stage-forceps ; the diaphragms have openings of various sizes, which may be
placed in immediate contact with the under surface of a slide if desired, and no
pains have been spared to provide for all the wants of the working microscopist
in every department of science in this one stand, which is believed to be at
least unexcelled by any other of its class. The objectives furnished with it
are those of our National series.

The Binocular "Ideal" Microscope Body is of the. same size as that of the
Economic, No. 264.*

36

R. & J. BECK, PHILADELPHIA.

No. 209.
One-half Actual Size.
The above illustration represents The "Ideal" Monocular Microscope Stand
(No. 209), and as furnished with No. 201. The glass stage is shown removed,
and the spring clips of the thin Diatom Stage in position.

R. & J. BECK, PHILADELPHIA. 37

Illustration in Next Edition.

No. 211.
Two-fifths Actual, Size.

The above illustration represents The "Ideal" Binocular Microscope Stand
(No. 211), and as supplied with No. 205. It shows the Glass Stage in position,
and the thin revolving stage and sub-stage ring removed; and the Mirror bar
at a very considerable inclination.

33 R. & J. BECK, PHILADELPHIA.

PRICES OF THE "IDEAL" MICROSCOPES AND APPARATUS.

No. Price.

200. The " Ideal " Microscope, Monocular, . . . . $70 00

With Swinging Sub-stage revolving around the upper Stage by a
graduated Circle with Centering Stop, very thin Circular Stage
with Clips, allowing the utmost obliquity of illumination, and
removable Stage-plate rotating concentrically in the Optic Axis.
Coarse adjustment by Rack and Pinion, and fine ditto by a deli-
cate Micrometer Screw, conveniently placed at rear "of arm,
moving the entire body without tremor ; Graduated Drawtube,
two Eye-pieces and two Objectives (one inch No. 295 and one-
sixth inch No. 298 of the National Series), Condensing Lens on
Stand No. 226, Stage Forceps and Pliers with Glass Plate.
The whole packed in handsome Mahogany Case with Drawer for
usual accessories.

201. The "Ideal" Microscope, Monocular, . . . . 75 00

With Stand the same in all particulars as that furnisbed with
No. 200, with the addition of a Movable Glass Stage with Stop
for Maltwood Finder, as shown in the illustration ; Objectives,
Eye-pieces and all other accessories the same as those furnished
with No. 200 — in handsome Mahogany Case.

205. The "Ideal" Microscope, Binocular, . . . . 100 00

With two pairs of Eye-pieces, adjustment for different widths .
between eyes, Glass Stage, Objectives and all accessories the
same as those furnished with Monocular Stand No. 200 — in
Mahogany Case.

208. The " Ideal " Microscope Stand, Monocular, . . . 45 00

Same as that furnished with No. 200 ; One Eye-piece. No ac-
cessories or case. . . . . .

209. The "Ideal" Microscope Stand, Monocular, . . . 55 00

With Movable Glass Stage same as that furnished with No. 201 ;
Two E3Te-pieces. No accessories or case.

211. The "Ideal" Microscope Stand, Binocular, . 75 03

With Movable Glass Stage, the same as that with Stand No. 205 ;
Two pairs of Eye-pieces. No accessories or case.

215. Mahogany Case for the Monocular "Ideal" Microscopes, . 6 50

216. Mahogany Case for the Binocular "Ideal" Microscopes, . 7 50

217. Mahogany Side Case, 3 50

Arranged to slide into either of the above Cases ( No. 215 or 216 ),
with Fittings for all the additional Apparatus ( Nos. 288 to 24S ).

220. Mechanical Stage, 22 50

With Horizontal and Vertical Movements and Sliding Object-
Holder, Revolving Concentrically in the Optic Axis.

221. The "Ideal" Iris Diaphragm, 7 50

222. Conical Diaphragm, 2 50

223. Adapter, , .... 2 00

For using an Object-glass as Condenser, Nos. 221, 222 and 223, are
specially fitted to the Sub-stages of the " Ideal" and Improved
National Microscopes.

224. Blue Glass Light-Moderator, 2

226. "Ideal" Side Condensing Lens, 3

On Stand, with Universal Movements.

227. Improved Stage Forceps, 2 50

50
50

R. <fe J. BECK, PHILADELPHIA.

39

THE "IDEAL" SERIES OF ACHROMATIC OBJECT-GLASSES.

The "Ideal" Object-glasses in the following list have been carefully formu-
lated and made to meet the wants of that largo and growing class of working
Microscopists, who, whilst requiring most exactingly the very highest perform-
ance in a lens, as to flatness of field, freedom from color, penetration, and per-
fect definition and resolution, do not care to pay the prices neccessarily charged
for fancy lenses, made regardless of cost. The " Ideal " Series fully meets all
these requirements, and we confidently recommend them as being superior in
all respects to any others of similar cost now made. From the 1 up they are
furnished with Cover Corrections.

234-34*

PRICE LIST OF OBJECT-GLASSES AND LIEBERKUHNS.

No.

Focal Linear magnifying power nearly,
length. with Eye-pieces.

229.

3

230.

2

231.

3K

232.

1

233.

Vo

234.

M

234*.

y«

235.

%

236.

i

■5(5

m.
in.
in.
in.
in.
in.
in.
in.
in.

Draw-tubes.

No. 1.

closed

12

'closed

24

closed

29

closed

55

closed

120

closed

210

closed

closed

420

closed

800

No. 2.
20
40
48
90
200
350

700
1200

No. 3.

40

70

90

160

360

600

1000
2000

Degrees

ofangle
of aper-

Price.

No.

ture.

$ c

8

16 00

10

13 00

15

20 00

237

22

20 00

1.38

40

20 00

219

75

20 00
30 00

85

40 00

100

60 00

Lieber-
kuhns for
Object-
glasses.

1%-inch

1-inch

34-inch

Price.

4 00
3 50
3 50

238.
240.
241.

242*

244.

245.
245*

246.
247.

248.
250.

253.
253*
254.
255.
256.
257.
262.

ADDITIONAL APPARATUS.

Lieberkuhn to 1-inch Object-glass, $ 3 50

Dark Well, . . . . . 2 00

Achromatic Condenser and Fitting, 8 50

. Wenham's Parabolic Reflector, for Dark-field Illumination,
specially adapted to the Sub-stages of the " Ideal" and Improved

National Microscopes, 8 50

Polarizing Apparatus, complete, with Prisms, Film of Selenite and

Adapter, . . . . . . . 15 00

Wollaston's Camera Lucida, for drawing an object, . . . . 6 50

. Vertical Camera Lucida, to bo used with the Microscope in an up-
right position, 8 00

Glass Micrometer, ruled into T^ths and TTJViyths of an inch, . . 2 25

Small Live Box, , . 2 50

Glass Trough, complete With Wedge and Spring, . . . . 3 00

All the Above Additional Apparatus, from Nos. 238-248, (not in-
cluding 245*), if ordered at once, . . . . . . . 45 00

Double Nosepiece, angular, 7 00

■. Triple Nosepiece, " 15 00

Series of Two dozon Popular objects in Case, 7 00

Series of Six Dozen Educational objects in Mahogany Case, , 30 00

Dr. Woodward's Diatom Prism, mounted, 1 50

Hemispherical Lens, mounted, 3 00

Eye-pieces for the " Ideal " Microscopes, Nos. 1, 2, 3, 4, or 5, each, . 5 50

40 It. & J. BECK, PHILADELPHIA.

THE LITH0L0GICAL MICROSCOPE.

The general form of The Lithological Microscope Stand is the same as that of
the "Ideal," and is sufficiently shown in the accompanjnng woodcut. Whilst
spesially constructed with a view to its employment by students of Mineralogy
and Petrology, it is equally efficient for the work of the general Microscopist,
as all of the apparatus of the " Ideal " and National Stands can be used upon it.

The body is provided with a Draw-tube (by which the Standard length of ten
inches may be obtained), the head of which carries a bevelled circle graduated as
shown in the illustration. A corresponding disc, with an index, is attached to the
bottom of the analyzer-fitting, and rests directly upon the fixed divided circle,
so that the analyzer can be set in any required position ; and any amount of
revolution imparted to it can also be registered. The eye-pieces — when
inserted — are kept in a fixed position by a stud, which falls into a slot. Delicate
crossed lines are fixed within the eye-pieces for the purpose of centering the
instrument. A plate of Calc spar, cut at right angles to the optical axis, is
mounted in a metal ring, which can be placed between the eye-glass and the
analyzer for stauroscopic examinations.

The nose-piece, carrying the Society screw, is attached to the Body by the
Butterfield or broad-gauge screw , and is provided with two small milled-heads
(shown in the illustration), by means of which any objective may be accurately
centered. It is also fitted with a Kleins quartz plate, set in a small brass mount.
When not in use the aperture is closed by a revolving collar.

The stage is circular, and capable of concentric rotation ; and it is divided on
the margin to 360°. A Vernier is attached to the front, and an index-point to the
back of the stage.

The polarizer slides into a fitting attached to an arm, which is pivoted on the
lower immovable surface of the stage, so that it can readily be displaced when
ordinary transmitted illumination is required ; and replaced with equal facility.

Two small lenses (as condenser), affording a strongly convergent pencil of
light, are set in metal rings -which drop into the top of the fitting which sur-
rounds the polarizing prism. When these are employed, and the analyzer is
used without the eye-piece (a separate fitting being supplied for this purpose),
examination of the rings and brushes presented by sections of certain crystals,
can be advantageously carried on. The lower end of the fitting which carries
the polarizer is surrounded by a graduated circle, turning beneath a fixed index,
so that any position of the prism can be recorded, and the rotation imparted to
it can be measured.

From the foregoing description it will be seen that this instrument is capable
of performing the functions of an ordinary Microscope, a Polariscope and a Stau-
roscope. A Spectroscope (No. 65 or 66), or a Goniometer (No. 156), can also be
employed if needful.

260. The Lithological Microscope Stand, $110 00

Stand as described above, with two eye-pieces ; Polariscope, with
condenser complete ; swinging Sub-stage and rotating upper
Stage— in handsome Mahogany case.

K. & J. BECK, PHILADELPHIA.

41

No. 260.

One-half Actual Size.
The above illustration represents very accurately the new Lithological Micro-
scope Stand, with Polarizing prism thrown out of position, sub-stage removed,
and Mirror inclined; and all the graduations, to stage, Polariscope and Eye-
piece ; with centering screws to nose-piece, and quartz-plate in position.

42 Tt. & J. BUCK, PHILADELPHIA.

THE ECONOMIC MICROSCOPE

The Microscope is now such an absolute necessity for the student, to enable
him satisfactorily to carry on his investigations, that it is more than ever in-
cumbent on the optician to construct a sound economic instrument, adapted to
the special requirements of this large and increasing class.

For ordinary pathological, physiological, and botanical investigations, many
of the delicate adjuncts applied to the higher-priced instruments are unnecessary,
and tend rather to confuse than to assist the beginner.

A firm Stand and well-corrected Object-glasses are, however, indispensable;
and, with a view to meet this want, we have constructed and now introduce to
the special attention of professors and students, the " Economic Microscope."

The description following will fully explain both the construction and the
mode of using this instrument; whilst the scale of prices at the conclusion will,
Ave trust, convince all who peruse them that we are able, bjr means of the
machinery at our command, to offer those who do not desire to spend a large
sum on a microscope, an instrument thoroughly adapted to their necessities, at
a very moderate outlay.

A Compound Achromatic 31icroscope, consists essentially of two parts, — an
Object-glass and an Eyepiece, — so called because they are respectively near the
object and the eye when the instrument is in use. The object-glass screws, and
the eyepiece slides, into opposite ends of a tube termed the Body, and upon the
union of the two the magnifying power depends. The Microscope Stand is an
arrangement for carrying the body, and is combined with a Stage for holding
or giving traverse to an object, and a Mirror or some other provision for
illumination.

The Stand of the Economic Microscope is made in two forms — the one with a
sliding coarse adjustment for focussing the object, and the other where the quick
movement is produced by a rack and pinion. On both stands the fine adjustment
is given by means of a milled head at the top of the stem. The Object-glasses
are attached to the stand with the Universal or Society Screw.

Description of the Stand (Fig. 1, No 263) and Apparatus as Supplied

for $45 00.

The foundation of the stand (Fig. 1, No. 263) is a heavy Tripod base, A,
from which rises a firm pillar, B, having at its top a hinge joint, C, which
allows the body, L>, to be inclined at any angle, and is sufficiently firm to
permit of its being placed horizontal for use with the Camera Lucida.

At this price the instrument includes one Eye-piece, No. 2, and two Object-
glasses, called the 1-inch and i-inch, from their magnifying power being nearly
the same as single lenses of such focal lengths, a condensing lens for the illumi-
nation of opaque objects, a glass plate with ledge, for examination of fluids, and
a pair of brass pliers. The whole packed in a neat Mahogany case, with lock
and key.

Its Linear Magnifying-poiocrs are nearly as under: —

Draw-tube closed. Praw-tube pulled out.

1-inch 63 li0

£-inch 240 330

The Body is supplied with a draw- or lengthening-tube, V. which must be
pulled out to give the fall power to the object-glass, F.

The Quick- focussing movement is produced by sliding the body, D, up and
down in the tube, G, and the slow motion is given by the tube, H, sliding over
the inner stem with a spring inside, and adjusted by the milled head, I.

R. & J. BECK, PHILADELPHIA.

43

The Stage, K, upon which the object is placed, has two springs, L, L, the pins
attached to which may be inserted in any of the four holes on the stage, and by
their pressure, (which can be varied by pushing them more or less down) they
will hold the object under them or allow it to be moved about with the greatest
accurac3r.

The Mirror, M, besides swinging in the rotating semicircle, N, is attached to a
bar, O, with a ioint at each end allowing a lateral movement, so as to throw
oblique light on the object; and for this purpose the tube beneath the stage,
carrying the Diaphragm is attached by bayonet catches, and can be instantly
removed, leaving a clear and very thin stage, allowing the utmost obliquity of
illumination. This tube also carries the Polariscopc, etc., etc.

The Diaphragm, P, slides in the substage-fitting, and consists of a tube con-
taining two caps furnishing two sizes of openings, immediately in contact with,
the under surface of the slide to be examined, and also completely cutting o£
all light from the mirror when opaque objects are to be viewed.

Fig. 1.

No. 263.
One-third Actual Size.

No.
263

Price.

The Monocular Economic Microscope, with Tripod base. Body
sliding in a cloth-lined tube for quick adjustment of focus and
delicate Micrometer Screw for fine ditto, with Draw Tube. Two
Object-Glasses, 1 inch and \ inch, and one Eye-piece, No. 2, giv-
ing powers from about 60 to 350 diameters. Condensing Lens,
Concave Mirror and Stage Forceps, etc. In Mahogany Case with
lock £45 00

44

R. & J. BECK, PHILADELPHIA.

Fig. 2.

No. 264.
One-half Actual Size.

Wo.
264

Prick.

TTie Monocular Economic Microscope, with Itack-and-Pinion adjust-
ment of focus, for the quick movement, and Micrometer Screw
for fine ; Draw-tube with Indicator at Standard length : Two Ob-
ject Glasses, 1 inch and \ inch, and two Eye-pieces, Nos. 2 and 3,
affording a range of powers from about 60 to 500 diameters. Plain
Stage, with delicate removable and adjustable Clips, Concave and
Plane Mirrors, Condensing Lens, Stage Forceps, Pliers and Glass
Plate with ledge. In Mahogany Case with lock $55 00

R. & J. BECK, PHILADELPHIA*

45

No. 264.*
No. One-half Actual Size. Price.

264*. The Monocular Economic Microscope, with movable Glass Stage,
and Draw Tube ; two Eye-pieces and two Object-glasses, i inch
and & inch focus, having a range of powers from about 100 to 750
diameters ; Stage Forceps, Pliers and Glass Plate with Ledge. In
Mahogany Case, . $65 00

46

.&, <fc J. BKCK. PHILADELPHIA.

No. 264.**
Two-fifths Actual Size.
264**. The Binocular Economic Microscope, with 1-inch and £-inch Object-
glasses, two pairs of Eye-pieces, concave and plane Mirrors, Side
Condensing Lens for the illumination of opaque objects, movable
glass stage, stage forceps, pliers and glass plate with ledge, in Mahog-
anyCase, ........

$85 00

E. & J. BECK, PHILADELPHIA. 47

DIRECTIONS FOR USE.

To adjust the focus of the Object-glass —

In Fig. 1, for the quick adjustment, slide the tube, D, up or down in the fit-
ting, G. If a slight spiral movement is given to the tube by the linger and thum b,
the motion may be made very gradual.

In Figs. 2 and 3, the same adjustment is made by turning the milled head
backward or forward.
In both, turning the milled head, I, gives the slow or fine adjustment.
The light (which for transparent objects is reflected from the mirror, M, and
for opaque objects is condensed by means of the lens, S) should, in general, be
upon the left of the observer if the microscope-body is inclined, but in front
if the Instrument is used in a vertical position. The best is that from a white
cloud on a bright day ; but a very satisfactory effect can be produced by means
of a petroleum-oil, or gas-lamp, provided it is placed not more than 10 or 12
inches from the Instrument.

For the examination of minute striae, side-light is necessary ; for this purpose
the mirror, M, must be used obliquely, the diaphragm, P, with its fitting re-
moved, which will then allow the light to impinge on the object at a sufficiently
oblique angle.

With the 1-inch Object-glass the light is generally in excess, and has to be
lessened by means of the diaghragm, P, fitting under the stage ; this can be slid
up and down, thereby increasing or decreasing the cone of admitted rays of
light.

To illuminate opaque objects the light is thrown upon them from above. A
small condensing-lens, fitting into the stage, is used for this purpose; its focus
for a lamp or candle, 4 inches from it, is about 3 inches ; for daylight 2 inches.
A large object can be placed upon the stage, but small ones are generally either
laid on a slip of glass or held in the forceps. When viewing opaque objects, the
diaphragm, P, should be placed in position and the solid cap attached, so as to
exclude all light from below the stage,

A glass plate, with a ledge and some pieces of thin glass, are applicable for
many purposes, but are specially intended for objects in fluid. Thus a drop is
placed upon the plate and covered by a piece of thin glass, or, the object being
put upon the plate and the thin glass over it, the fluid is applied near one side
and runs under by capillary attraction.

Glass of any kind requires occasional cleaning ; a piece of soft wash-leather is
the best for the purpose.

The fronts of the Object-glasses may be carefully wiped ; but if they require
anything more, it must be done by the makers.

When cleaning the Eye-pieces, which should be done frequently, the cells con-
taining the glasses must be unscrewed, and replaced one at a time, so that they
may not be mixed.

Any dirt upon the Eye-pieces may be detected by turning them round whilst
looking through the Instrument; but if the Object-glasses are not clean, or are
injured, it will for the most part only be seen by the object appearing misty.

The whole or any part of the extra apparatus described in the following pages
may be added to the instrument at any time, without its being sent back to
the makers.

ADDITIONAL APPARATUS.

Although the Instrument, as already described, may be considered complete
and probably sufficient for many observers, yet the following additions can be
made, all of which, packed in a small tray, will fit into the case which contains
the Microscope:

48

E. & J. BECK, PHILADELPHIA.

When the light from the concave mirror proves insufficient for any object
requiring an intense transmitted light, the Acromatic Condenser (No. 241, Fig. 3)
may be employed with advantage : this slides, by its tube, into the fitting under
the stage of the Instrument, in which it has to be moved up or down until the focus
of its lenses falls upon the object, the light having been previously reflected in
the proper direction by the mirror.

Fig. 3.

241.

Fig. 7.

The Illumination of Opaque Objects, already described, must be more or less
one-sided ; and in most cases it is desirable that it should be so. An illumina-
tion on any or every side, however, is easily obtained, provided the object is not
too large, by means of the Lieberkuhn (No. 238*, Fig. 4). This is a silvered cup,
which slides or screws upon the front of the object-glass; and light thrown up-
wards by the mirror will be reflected by it down upon the object ; it will then
be found that, by slightly varying the inclination of the mirror, every necessary
alteration in the direction of the illumination can be obtained. The Lieberkuhn
here shown is intended for the 1-inch object-glass.

It is in most cases necessary, when using the Lieberkuhn, to slide a Dark
Well (No. 240, Fig. 5) under the stage to prevent any light entering the Object-
glass direct from the Mirror.

Dark-Field Illumination is, to appearance, a means of seeing
a transparent object as an opaque one. The principle, however,
is that all the light shall be thrown under the object, but so ob-
liquely that it cannot enter the Object-glass unless interrupted by
the object ; this is best accomplished by Wenham's Parabolic Re-
flector (No. 242, Fig. 7).

In this Microscope, the Parabolic Reflector fits under the stage
in the same fitting as the achromatic condenser, and the adjust-
ment of its focus upon the object (which is when its apex almost
touches it) is made by giving it a spiral motion in the fitting— that is, carefully
pushing it up or down at the same time that it is turned round by the milled
cclo-e, B. B. As the rays of light must be parallel when they enter it, the Flat
Mirror is generally used; daylight will then require only
direct reflection, but the rays from an artificial source will
have to be made parallel by putting the Condenser (No. 260)
between the light and the mirror, about If inches from the
former, and 4| inches from the latter. Nearly the whole
surface of the mirror should be equally illuminated, which
may be tested by temporarily placing upon it a card or piece of
white paper.

Polarized Light, a beautiful appliance by which many objects
otherwise almost invisible are shown in every imaginable
color, can here only be treated of by describing the way in
which it is applied to this Microscope by the following appa-
ratus (No. 244*, Fig. 8) : A Nicol's prism as a polarizer, A,
fits, and can be turned round, in the fitting under the stage ; an-
other prism, B, is fitted to an adapter which screws above
the object-glass, and also revolves. When only alternate
black and white images are given by the prisms alone, a film of selenite, fitted
in a cap which slips over the Polarizing prism, will produce colored ones.

No. 242.

Fig. 8.

E. & J. BECK, PHILADELPHIA.

49

To draw an object, the Camera Lucida (No. 245,) is used. It slides on in the
place of the cap of either Eye-piece, with its flat side uppermost, as shown.
The body of the Microscope must be in a horizontal position, and the whole
instrument has to be raised until the edge of the prism is exactly 10 inches from
a piece of paper placed upon the table. The light must be so regulated that no
more than is really necessary is upon the object, whilst a full light should be
thrown upon the paper. Only one eye is to be used ; and if one-half of the pupil
be directed over the edge of the prism, the object will appear upon the paper, and
can be traced on it by a pencil, the point of which will also be seen.

With the Vertical Camera Lucida, (No. 245*), the Microscope remains in an
upright position, and the paper upon which the drawing is to be made, can be
placed either at the side or in front of the instrument. This form of Camera is
specially adapted for use with The Histological Microscope, (No. 340).

No. 245*

No. 245.

Substituting in the place of the object a piece of glass ruled into lOOths and
lOOOths of an inch, termed a Micrometer (No. 246, Fig. 10), its divisions can be
marked on the same or another piece of paper, and, by comparing them with
the sketch, the object can be most accurately measured. These divisions, also,
if compared with a rule divided into inches and tenths, will give the magnifying
power: thus, supposing x^ths of an inch when marked on the paper measured 1
inch and -£$, the magnifying power would be 130.

The Live-box (No. 247, Fig. 11) hardly needs description ; the object is confined
between the glass, a, of the lower part, B, and that of the cap C ; the distance
between them can be varied by sliding the latter more or less on. As the thin
glass is only dropped into a slight recess in the top of the cap, and is held there
by the heads of the two screws, it can be easily taken out for wiping, or be re-
placed by another when broken.

The Glass Trough (No. 248, Fig. 12), for larger objects in water, must be used
with its thinner plate of glass, b, in front. The modes of confining such objects,

Fig. 10.

Fig. 12.

No. 246.

and keeping them near the front surface, must vary according to the occasion.
For many it is a good plan to place a piece of glass, e, diagonally in the trough,
its lower edge being kept in its place by a strip (d) at the bottom ; then if the ob-
ject introduced is heavier than water, it will sink till stopped by the sloping
plate. Sometimes a very slight spring (/) may be applied behind this plate to
advantage, with a wedge (g) in front to regulate the depth.

50 R. & J. BECK, PHILADELPHIA.

PRICES OF THE ECONOMIC MICROSCOPE AND APPARATUS.

So. Price.

263. The Monocular Economic Microscope, with sliding coarse ad-

justment, 1-inch and i-inch Object-glasses, one Eye-piece, Concave
Mirror, condensing lens, glass plate with ledge, brass pliers and
Diaphragm, in Mahogany Case, ^45 qq

264. The Monocular Economic Microscope, with Rack-and-pinion

coarse adjustment, with 1-inch and i-inch Object-glasses, two Eye-
pieces, Concave and Plane Mirrors, side Condensing-Lens, Dia-
phragm, Stage-Forceps, Pliers, Glass slip, with ledge, in Mahogany

Case, 55 00

264*. The Monocular Economic Microscope, with Movable Glass
Stage 1 inch and I inch objectives, and the same fittings and case

as with No. 264, . 65 00

264**. The Binocular Economic Microscope, with Movable Glass Stage,
Concave and Plane Mirrors, a side Condensing-Lens for the
illumination of opaque objects, lever adjustment for different
widths of eyes, two pairs of Eye-pieces, the same objectives and
accessories as with No. 264*, in Mahogany Case, . . . 85 00

263*. The Monocular Economic Microscope-Stand, the same as

with No. 263, with two Eye-pieces and Mahogany Case, . . 32 50
264b. The Monocular Economic Microscope-Stand, the same as

with No. 264, with two Eye-pieces and Mahogany Case, . . 37 50
264c. The Monocular Economic Microscope-Stand, the same as
with No. 264*, with two Eye-pieces, Movable Glass Stage, side

Condensing-Lens and Mahogany Case, 50 00

264e. The Binocular Economic Microscope-Stand, the same as with
No. 264**, with two pairs of Eye-pieces, Movable Glass Stage,
side Condensing-Lens and Mahogany Case, . . . . 65 00

265. Eye-Pieces for 340-42. Nos. 1, 2 or 3, each, . * . . . 4 50
265r::-EYE-PiECEs for the Economic Microscopes. Nos. 1, 2 or 3, each, . 5 00

266. Side Condensing-Lens, . " . . .' ." . . 2 50

267. Stage-Forceps, 2 50

26& Pliers, : ,. 5U

ADDITIONAL APPARATUS.

238*.Lieberkuhn to 1-inch Object-Glass, 3 50

240. Dark Well, 2 00

241. Achromatic Condenser and Fitting, . . . . • . . 8 50

242. Wenham's Parabolic Reflector, for Dark-field Illumination, . 8 50
243*.Flat Mirror for 263 (in which case a double one is substituted for

the concave single one, which has to be returned), . . . . 3 00
244*. Polarizing Apparatus, complete with Prisms, film of Selenite,

and adapter,, . . . . » . . . . . . . 13 50

245. Wollaston's Camera Lucida, for drawing an object, . . . 6 50
245* Vertical Camera Lucida, 8 00

246. Glass Micrometer, ruled into xfayths and y^ths of an inch, . 2 25

247. Small Live-Box, . . 2 50

248. Glass Trough, complete with Wedge and Spring, . . . . 3 00
249*. All the above "Additional Apparatus," from Nos. 239* to 248,

• £not including .245*)^ if ordered at once, . . . . . .45 00

R. & J. BECK, PHILADELPHIA. 51

THE NEW NATIONAL MICROSCOPE.

In the three years that have elapsed since we brought out the New National
Microscope we have sold many hundreds of the same, and the sale is steadily on
the increase. It is used in most of the Colleges and Hospitals throughout the
country, and is universally and deservedly pronounced to be the best instru-
ment ever made at the price. The utmost care has been taken throughout to
introduce only the best workmanship into its construction, and, mechanically
and optically, it is as nearly perfect as possible. The design of the stand is
graceful and pleasing, it is well balanced in all positions, and is adapted to every
variety of work, whilst its general finish and appearance are most elegant.
Every variety of accessory apparatus can be used with it, and the pieces specially
constructed for it are of the best description, and of very moderate cost.

The Glass Stage — moving with exquisite smoothness in any desired direction,
and revolving with such accuracy that an object in the field of the £-inch is not
thrown out of view — is usually all that any observer needs. If, however, the
movement of the object requires greater nicety than a direct action from the
hand can give, this stage can be taken off, and replaced by the Mechanical Stage
(No. 290), which has very smooth vertical and horizontal movements by means
of Milled-Heads ; and can also be revolved concentrically, the same as the plain
Glass Stage.

The National iSeries of Objectives has most deservedly acquired a National
reputation ; several thousand of them are in use, and we confidently assert that
no other lenses of their cost are in any manner comparable with them. Their
corrections are of the most perfect character, and in all the qualities of good
working glasses they have never been excelled, whilst their low cost leaves no
excuse for the employment of cheap (and " nasty") French Triplets, as heretofore,
by those who do not care to pay the prices demanded for the highest grades of
Objectives. ^

In order to meet the wants of those who require greater power we have recently
replaced the i-inch objective heretofore furnished with Nos. 275 and 276, with a
£-inch. The I will still be furnished to those who prefer it to the £th. If desired
the S-inch (No. 296) will also be furnished with these two Microscopes in place of
the usual 1-inch without extra charge.

We shall strive to maintain the position of The New National Microscope by
taking the greatest care in the selection of the Object-glasses and. all Accessories,
and by using every effort to perfect the brass work, and doubt not that such
efforts will obtain a still more extensive sale for it.

DESCRIPTION OP THE NEW NATIONAL MICROSCOPE.

The Stand, which is 15 inches in height, is constructed entirely of brass, of
the highest finish and best workmanship, having a broad, heavy tripod base.
From the centre of this base rises a stout column, to the top of which is attached,
by a firm joint, the Jackson-model arm, carrying the compound body, by which

52

R. & J. BECK, PHILADELPHIA.

THE NEW NATIONAL BINOCULAR MICROSCOPE.

No. 279.
One-third Actual Size.
Che above Illustration represents The New National Binocular Stand, (No.
♦279), and as furnished with No. 275. The Revolving Glass Stage is the same as
that furnished with the Monocular stand, (No. 280).

R. & J. BECK, PHILADELPHIA.

53

THE NEW NATIONAL MONOCULAR MICROSCOPE.

No. 280, with 290 and 253.*
One-third actual size.

The above Illustration represents The New National Monocular Stand, (No.
280), and as furnished with No. 276; to which are added Triple Nose-piece, (No.
253*), and Mechanical Stage, (No. 290), to show the same in position.

54 E- & J- BECK, PHILADELPHIA.

the inclination can be varied to any degree, from vertical to horizontal, the whole
instrument being perfectly steady and free from tremor in any position. The
very highest powers may be used with it, as the body, being supported by the
arm throughout its entire length, cannot have any unsteadiness or motion of
its own.

The quick Adjustment of Focus is effected by means of Rack and Pinion,
with large Milled Heads, which works so smoothly that there is no need to use
the Fine Adjustment for any power lower than i of an inch. The latter adjust-
ment is by means of a delicate Micrometer screw and lever attachment, work-
ing with absolute freedom from all motion, and by which the very highest
powers may be focused with the greatest exactness.

The Stage is of glass, with a complete rotation in the Optic Axis, upon the top
of which is a sliding object-holder, very thin, and with a spring clip for holding
the object in place during rotation. This clip is removable, in an instant, and
the Stage forceps can be inserted in its place, thus allowing the latter to be
moved about with the object-carrier. Beneath the Stage is a tube carding all
the sub-stage apparatus, as the Achromatic Condenser, Wenham's Parabola,
Polarizing Apparatus, etc., etc. This is securely attached to the Stage by a
bayonet catch, and can be instantly detached, leaving a very thin and unob-
structed Stage for Oblique Illumination. The Shutter Diaphragm is of novel
construction, with the various sized openings almost in contact with the under-
side of the object under examination, a great improvement upon the old re-
volving disk Diaphragm. A Double Mirror Concave and Plane is hung upon a
swinging bar, and arranged with every possible motion for Direct and Oblique
Illumination.

The Accessories and their Use are fully described on pages 47, 48 and 49 of
this Catalogue; those supplied with the Popular, Economic and National
Stands, being essentially the same, and equally applicable to either Instrument.

WENHAM'S BINOCULAR BODY.

Thus far in this description the Microscope has only been considered as
having a single body ; the addition, therefore, of the Binocular Body, shown in
section by the accompanying figure, requires a few explanations and directions
for use.

The purpose of the Binocular Microscope is to give stereoscopic vision of
objects, Avhereby the form, distance and position of the various parts are in-
stantly seen ; and the result is almost as striking as if the minutest object were
placed in the hand as a model.

To accomplish this, the only plan yet known is the equal division of the rays
after they have passed through the object-glass, so that each eye may be fur-
nished with an appropriate one-sided view of the object ; but the methods
hitherto contrived to effect this not only materially injure the definition of the
object-glasses, but also require expensive alterations in their adaptation, or,
more frequently still, a separate stand ; whereas, the following arrangement,
contrived by Mr. Wenham, is no obstacle to the use of the Monocular Instru-
ment, and the definition even of the highest powers is scarcely impaired. It
consists of a small prism mounted in a brass box, A, which slides into an open-
ing immediately above the object-glass, and reflects one-half of the rays, which
form an image of the object, into an additional tube, B, attached at an inclina-
tion to the ordinary body, C. One-half of the rays take the usual course, with
their performance unaltered : and the remainder, although reflected twice,
show no loss of light or definition worthy of notice, if the prism be well made, i

As the eyes of different persons are not the same distance apart, the first and
most important point to observe in using the Binocular is that each eye has a
full and clear view of the object; this is easily tried by closing each eye alter-

E. & J. BECK, PHILADELPHIA.

55

nately without moving the head, when it may be found that some adjustment is
necessary by racking out the draw-tubes, D, E, of the bodies by means of the
small milled head, near the eye-pieces ; this will increase the distance of the

centres ; and, on the contrary, the tubes,
when racked down, will suit those eyes
that are nearer together.

If the prism be drawn back till stopped
by the small milled head, the field of
view in the inclined body is darkened,
and the rays from the whole aperture of
the object-glass pass into the main body
as usual, neither the prism nor the addi-
tional body interfering in any way with
its use as a Monocular Microscope.

By unscrewing the small milled head,
the prism can be withdrawn altogether
for the purpose of being wiped ; this
should be done frequently, and very carefully,
on all four surfaces, with a perfectly clean cam-
bric or silk handkerchief or a piece of wash-
leather ; but no hard substance must be used.
During this process the small piece of black-
ened cork fitted between the prism and the
thick end of the brass box may be removed ;
but it must be carefully replaced in the same
position, as it serves an important purpose in stop-
ping out extraneous light.

As the Binocular Microscope gives a real and
natural appearance to objects, this effect is con-
siderably increased by employing those kinds of
illumination to which the naked eye is accustomed.
The most suitable are all the opaque methods where
the light is thrown down upon the surface ; but for
those objects that are semi-transparent, as sections
* of Bone or Teeth, Diatomacese, living aquatic Ani-

malcules, etc., the dark-field illumination by means
of the parabolic reflector (No. 242) will give an equally
good result.

For perfectly transparent illumination, it is much better
to diffuse the light by placing under the object various
substances, such as tissue-paper, ground glass, very thin
porcelain, a thin film of yellow bees' -wax, run between
two pieces of thin glass, or a slip of Cobalt blue glass with
ground surface.

The Wenham Prism of The Improved Binocular National
Microscope, is fitted in a Nose-piece which is attached to the
Compound Body by the "Broad Gauge" or Butterfiekl
Screw, held firmly in proper position by a pin as shown in
the illustration on Page 57. This Nose-piece can be entirely
removed, leaving the body or tube entirely free from dia-
phragms or other obstructions, permitting the use of objec-
tives bearing the above-named Screw ; or by means of an Adapter, with Society
Screw (which is also furnished with the Stand), ordinary objectives of the widest
apertures.

With each " Ideal," Economic or National Microscope sold by us at retail, one
dozen assorted objects of the Popular Series in a neat box are furnished.

56 R. & J. BECK, PHILADELPHIA.

DESCRIPTION OP THE IMPROVED NATIONAL MICROSCOPE.

Although the popularity of the New National Microscope continues to grow
steadily, there has arisen a demand among certain Microscopists for additions
to that instrument which we can no longer resist, and following the initiative
taken in the production of our " Ideal" Stand, have now introduced the same
general features, with others peculiarly its own, into the Improved National
Microscope, which we present and recommend as being far superior to any of
its class and cost heretofore produced.

The general form and design of the Improved instrument are the same as
those of the old one, and with the alterations and additions can be readily com-
prehended by a glance at the accompanying illustrations. The admirable
rotating glass stage, with its movable slide holder, have been retained without
alterations, excepting the addition of a stop for Maltwood's Finder, and a con-
siderable reduction in thickness. The triangular bar carrying the Mirror and
Sub-stage revolves around the Main Stage, as in the "Ideal" Microscope, upon
a graduated circle, by which the degree of obliquity of illumination can be ac-
curately read. There is a Centering Stop to this swinging bar in the Optic
Axis, and as it is arranged to swing above the stage, the Mirror can be used for
Opaque illumination, although a Condensing Lens on Stand is also provided for
this purpose. The Mirror, which is double (concave and plane), slides up and
down upon this bar, and is provided with every needful adjustment. The Sub-
stage carrying all forms of illuminating apparatus is adjusted by Rack and
Pinion.

The Wenham prism in the Binocular Stand is mounted in a nosepiece
which can be entirely removed from the Compound body, leaving the
full-sized tube, without diaphragm, to receive an objective bearing the
Broad-gauge or Butterfield Screw, or an adaj)ter with Society Screw
(which is provided with each stand), whereby objectives of the widest
angles may be employed as with an ordinary Monocular tube. The
Monocular Stand is likewise provided with the same adapter to permit the use
of the Broad-gauge Screw. This necessitates the removal of the fine adjustment
from the nosepiece as in the old form of Nationals, and in the Improved form
it will be found placed conveniently at the rear of the limb bearing the Com-
pound body ; a large milled head moving the latter with the greatest smooth-
ness and delicacy. The workmanship and finish throughout are of the best,
and the Stand may be fairly called First-class. The construction of the Sub-
stage is such that nearly all the apparatus from No. 65 to 183 of this Catalogue
may be used upon it, in addition to that which is especially designed for it.

As will be seen from the accompanying Price List, we have fitted the Improved
Nationals with two Series of Objectives, the first and cheaper being those of our
old and well known National grade, the others the " Ideal " class, which are of
a still higher quality with cover correction for the & inch. At their respective
costs either of these series of objectives are superior to all others now made, and
are fully equal to all the demands of true workers, possessing the real require-
ments ot flatness of field, freedom from color, penetration, and great de-
fining powers.

R. & J. BECK, PHILADELPHIA.

57

THE IMPROVED NATIONAL BINOCULAR MICROSCOPE.

No. 279*.
One-third Actual, Size.
The above illustration represents The Improved National Binocular Stand
(No. 279*) and as furnished with Nos. 275*-275**. It shows the Swinging Sub-
stage inclined at a slight angle, with graduated circle around which it swings,
and Shutter Diaphragm in position, together with Rack and Pinion to Sub-stage;
also Fine Adjustment Screw and Removable Nosepieee carrying Binocular
Prism.

58 R. & J. BECK, PHILADELPHIA.

THE IMPROVED NATIONAL MONOCULAR MICROSCOPE.

No. 280*.

ONE-THIRP ACTUAL STZli.

The above illustration represents The Improved National Monocular Stand
(No. 280*), and as furnished with Nos. 276* and 276**. It shows the Swinging
Sub-stage, inclined from the observer at a considerable angle, with the Mirror
and Ring for carrying the Accessories in position. The Shutter Diaphragm is
removed, but shown on the table together with the Conical one, No. 222. m

K. & J. BECK, PHILADELPHIA. 59

PRICES OF THE IMPROVED NATIONAL MICROSCOPES.

No. Prick.

275. The New Binocular National Microscope, .... $no oo

With Concentrically Rotating Glass /Stage, and 1-inch (No. 295)
and J-inch (No. 298*) Object-glasses, having the respective aper-
tures of 19 and 85 degrees, and magnifying from about 47 to GOO
diameters, two pairs of Eye-pieces (No. 262), Stage Forceps (No.
227), Condensing Lens on Stand (No. 291), a Glass Plate, with Ledge
for the examination of objects in fluid, and a pair of Pliers; the
whole packed in French polished Mahogany case, with brass
handle and lock, and fittings for the accessories.

276. The New Monocular National Microscope, . . 85 oo

With Two Eye-pieces and the same Object-glasses and fittings as
with No. 275 — in Mahogany case.

279. The New Binocular National Microscope Stand, . 75 00

With one pair of Eye-pieces, Concave and Plane Mirrors, Shut-
ter Diaphragm, Stage Forceps, Glass Plate, and Pliers.

280. The New Monocular National Microscope Stand, . 50 to

With one Eye-piece, Concave and Plane Mirrors, Shutter Dia-
phragm, Stage Forceps, Glass Plate, and Pliers.

275-. The Improved Binocular National Microscope, . . 125 00

With Concentrically Rotating Glass Stage, and Swinging Sub-
stage, fitted with Rack and Pinion, new Fine adjustment, and
removable Nosepiece, 1-inch (No. 295) and &-inch (No. 298*)
Object-glasses, Two pairs of Eye-pieces (No. 262), Stage Forceps
(No. 227), Condensing Lens on Stand (No. 291), a Glass Plate
with Ledge and a pair of Pliers — the whole packed in an elegant
French polished Mahogany case, with good brass handle and
lock, and a drawer for the accessories.

276*. The Improved Monocular National Microscope, . . . 100 00

With Concentrically Rotating Glass Stage, and Swinging Sub-
stage, fitted with Rack and Pinion, new Fine adjustment, and
all the recent improvements, 1-inch (No. 295) and £ -inch (No.
298*) Object-glasses, Two Eye-pieces (No. 262), Stage Forceps
(No. 227), Condensing Lens on Stand (No. 291), Glass Plate with
Ledge and Pliers — packed in Mahogany case,with drawer.

275**. The Improved Binocular National Microscope, . . . 150 00'

With Concentrically Rotating Glass Stage, with Stop for Malt-
wood Finder, and Swinging Sub-stage, fitted with Rack and
Pinion, new Fine Adjustment, and and all the recent improve-
ments: 1-inch (No. 232) and £-inch (No. 234*) Object-glasses, of
the "Ideal" Series, Two pairs of Eye-pieces (No. 262), Double
Nose-piece (No. 253), Stage Forceps (No. 227), Condensing Lens
on Stand (No. 291), and Glass Plate with Ledge and Pliers. — In
Mahogany Case with Drawer.

276**. The Improved Monocular National Microscope, . . 125 00

With Two Eye-pieces, Stand, Object Glasses, and all apparatus
precisely the same as those with No. 275** — in Mahogany case.

279#. The Improved Binocular National Microscope Stand, 100 00

With Swinging Sub-stage and all improvements, Two pairs of
Eye-pieces, Diaphragm, Stage Forceps, Glsss Plate and Pliers.

280*. The Improved Monocular National Microscope Stand, . 75 00

With Swinging Sub-stage and all improvements, Two Eye-
pieces, Diaphragm, Stage Forceps, Glass Plate and Pliers.

281. Mahogany Cabinet for the New National Microscopes, . 12 00

282. " " " " " " " . 17 50

With Sidecase and Fittings for all Accessories, 239* to 248.

60

R. & J^ BECK^ PHILADELPHIA.

NEW NATIONAL SERIES OF OBJECTIVES.

293

294

295

296

297

298

299

300

In order to meet the universal demand for good and well corrected Object-
glasses, adapted to the wants of true observers, who need reliable glasses at a
moderate cost, impossible in lenses of the very highest grade, we have now
introduced our New National Series, which we confidently recommend as the
best low-priced Objectives ever made. They are corrected with great care, aro
exceedingly well mounted, furnished with the Society Screw, and packed in
handsome engraved Brass Boxes. The Series is as follows:

Focal

Linear magnifying power nearly,

Degrees of

No.

length.

with Eye-pieces.

angle of
apeiture.

Price

Draw-tubes.

No. 1. No. 2.

No. 3.

$ c.

293.

3 in.

closed

12

20

32

7°

7 00

294.

2 in.

closed

23

43

70

10°

7 00

2U5.

1 in.

closed

47

78

116

19°

9 00

296.

§ in-

closed

65

110

170

25°

10 00

297.

I in.

closed

100

170

260

38°

12 00

298.

1 in.

closed

200

340

520

75°

12 00

298*.

i in.

closed

275

480

750

85°

15 00

299.

i in.

closed

365

620

965

95°

20 00

300.

fV in.

closed

730

1240

1930

110°

30 00

301.

zV in-

closed

900

1550

2500

120°

45 00

J

239*
240.
241.
242.
244.

245.
24Fi*
L46.
247.

248.
250*

222.
253.

253*
262.
290.

291.

292.

ADDITIONAL APPARATUS.

.Lieberkuhn to 1-inch Object-glass,

Dark Well,

Achromatic Condenser and Fitting,

Wenham's Parabolic Reflector, for Dark-field Illumination, .

Polarizing Apparatus, complete with Prisms, Film of Selenite and
Adapter,

Wollaston\s Camera Lucida, for drawing an object, ....

Vertical Camera Lucida,

Glass Micrometer, ruled into T^hs and i^ths of an inch,

Small Live-Box,

Glass Trough, complete with Wedge and Spring, ....

.All the above Additional Apparatus, from Nos. 239* to 248 (not in-
cluding 245*), if ordered at once,

New Conical Diaphragm,

Double Nose-Piece, Angular,

.Triple Nose-Piece,

Eye-pieces, Nos. 1, 2, 3, 4 or 5, each,

Stage, with Horizontal and Vertical Mechanical Movements, Slid-
ing Object-holder, and Revolving Fitting complete,

Condensing Lens, on Stand, :

Draw-tube for "The National Microscope,"

$3 50

2 00

8 50

15 00

6 50

8 00

2 25

2 50

3 00

45 00

2 50

7 CO

15 00

5 50

22 50

6 00

3 50

R. & J. BECK, PHILADELPHIA.

Ct

No. 239*.

No. 240.

No. 241.

No. 242.

No. 244.

No. 245.

No. 246.

No. 247,

No. 248.

No. 262, No. 2.

No. 262, No. 3.

No. 253.

No. 245*

No. 253*.

62

R. & J. BECK, PHILADELPHIA,

HOLMES'S LECTURE ROOM MICROSCOPE.

No. 305.

305. Holmes's Lecture Room Microscope, stand only as figured, . $15 oo

The "Holmes's Lecture Room Microscope" was originally designed by Dr.
O. W. Holmes, of Boston, for use in his own class. By slight modifications of
his original plan, we have succeeded in producing the instrument in a somewhat
improved form, and feel assured it exactly fills a long-felt want, combining as
it does a perfect Class microscope, with a very excellent and practical stand for
all ordinary table use. Supported on a base of polished walnut by a column of
the same wood (which forms the handle for class use), is a light frame of brass,
bearing upon its upper surface, at an angle most convenient for observation, a
short, split tube, through which the compound body slides with perfect smooth-
ness, forming the coarse adjustment for focus. The fine adjustment is effected
by a micrometer screw and lever beneath the stage. The latter is furnished with
light spring clips, for holding the object, and a revolving diaphragm with differ-
ent-sized openings. The compound body is furnished with a first-class eye-piece
(A or B, as desired) ; and the " /Society Screw,'' whereby any objective of standard
English or American make can be used on it. A coal-oil lamp on adjustable
stand, firmly secured to the base of the instrument, furnishes the illumination.
For transparent objects, the light from the edge or width of the flame is allowed
to fall directly upon the object, through the central aperture of the stage. For
opaque objects, the lamp is raised to the top of its stand, and its rays allowed to
fall upon a small concave mirror attached to the brass frame by an universal
joint, whence they are reflected upon the object. The entire height of the in-
strument is about twelve inches, size of base ten by four inches, weight two and
three-quarter pounds.
307 Holmes's Lecture-Boom Microsope Stand, the same as 305, with

addition of adjustable mirror for use by daylight, . . . . §20 00

K. & J. BECK, PHILADELPHIA.

IMPROVED DISSECTING MICROSCOPE.

63

No. 308.

308. Improved Dissecting Single Microscope, $42 50

Stand with complete sliding and revolving Stage-plates; One
Arm to carry the lenses, with rack-and-pinion adjustment; Side
Condenser on lengthening arm; Mirror with complete adjust-
ments; Two single lenses and Two Coddmgtons, | and £-inch
focus ; the whole packed in a strong Mahogany Case.

ADDITIONAL APPARATUS.

309. Coddington Lens, 1-inch focus, $6 00

310. 4i " i-inch focus, 6 00

311. ** " |-inch focus, 6 00

312. Holder for Glass Slips, 2 00

313. Two Brass Saucers with Glass Bottoms, . . . . . . 2 50

314. Two Flat Glasses, 85

315. Two Concave Glasses, 2 00

316. One Piece of Box- wood covered with Cork, 65

217. One Gutta-Percha Tray loaded with Lead, 85

318. One Piece of Lead and Cork, 65

319. One Pair of Steel Forceps, 1 25

320. Two Pairs of Scissors, 3 50

321. One Needle-holder, 2 00

122. Two Knives, 2 00

323. Two Hooks, 1 75

324. Two Points, 1 75

325. Wooden Tray for holding Dissecting Instruments, . . . . 2 75

326. Box for containing additional Apparatus, 2 75

327. All the above Additional Apparatus, from Nos. 309-326, if ordered

at once, 40 00

328. Binocular Prisms and Arm for carrying ditto, 20 00

64

R. & J. DECK, PHILADELPHIA.

N^W MODEL DISSECTING MICROSCOPE.

No. 330.
One-half Actual Size.

330. New Model Dissecting Single Microscope, . . . . . $15 oo

Stand all brass, with broad circular Base and large firm Stage
with Spring Clips for holding a slide, and small concave glass
Saucer ; Jointed Arm to carry the lenses, with rack-and-pinion
adjustment of focus; Concave Mirror and Side Condensing Lens
with complete adjustments; two dissecting needles in holders and
one pair of brass forceps, two single lenses of H and 1-inch focus ;
the whole packed in a strong Mahogany Case with handle and lock.

331. New Model Dissecting Single Microscope, stand only, with one

Lens ; no Case or Condenser, 10 00

332. Single Lens of 1-inch focus, 2 50

333. " «.«•$••« . 2 50

3>1. Coddington Lens of 1-inch focus 6 00

338. " •««£■« .« 6 00

838. Hand Rests which can be immediately attached to both sides of the

stage, and removed at pleasure, 2 50

This instrument has been specially designed to meet a long-felt want for a
thoroughly good dissecting Microscope, at a very moderate cost. The Stand
is very firm, with a roomy Stage of the exact height from table for convenient
use ; the lenses are exceedingly good, and of the most useful powers and the
whole will be found very satisfactory for most purposes. Any of the acopsso
ries from Nos. 309 to 326 can be used with it. accesso-

R. & J. BECK, PHILADELPHIA.

NEW HISTOLOGICAL DISSECTING MICROSCOPE.

65

F.V.H

No. 340. No. 340.

One-third Actual Size.
No. Price

340. The New Histological Dissecting Microscope, with outfit as de-

scribed below, $25 0(

This instrument combines a Compound Microscope with a Single and Dissect-
ing one in a very compact, practical and economical form. The stout immovable
arm carrying the lens when used as a Single Microscope, is so arranged that a
compound body with Eye-piece and draw tube may be attached to its upper sur-
face, whilst beneath it is fitted with the Society Screw, whereby any objective
may be used with it. The Rack-and-Pinion adjustment work so smoothly that
a i-inch objective may be focused with the utmost exactness. The Mirror be-
neath the stage is so adjusted upon a swinging arm that it may be turned up
over the stage for the illumination of an opaque object. A revolving diaphragm,
with various sized openings, is attached to the under side of the stage. The out-
fit consists of a single lens of one-inch focus for dissecting and botanical work,
and an achromatic objective of i-inch focus, the same as furnished with the
Economic Microscopes, and one Eye-piece, giving a range of powers, with the
draw tube, of between 200 and 300 diameters, a pair of brass pliers, two dissect-
ing needles in Ebony handles and a glass plate with ledge. The whole packed
in a neat Mahogany case with lock. Any of the accessories 309 to 326 are ap-
plicable to this instrument.

341. The New Histological Dissecting Microscope, with the same out-

fit as with 340, and the addition of the Economic 1-inch Objective, 32 00

CO R. & J. BECK, PHILADELPHIA.

THE 'SCHOLARS' MICROSCOPE.

Price, §25 00.
Illustration and Description in Next Edition.

R. & J. BECK, PHILADELPHIA.

G7

CODDINGTON LENSES, etc.

No. 343.

Kos. 355-358.

No.
343.

344.

346.
347.
348.
349.
350.
351.
352.
353.

Price.
Combination of Three Lenses, mounted in Tortoise-shell, on Brass
Stand, with Adjusting Arms and Sliding Forceps for holding an

object, $13 50

Combination of Three Lenses, in Tortoise-shell, on Brass Stand,

with Adjusting Arm, 7 CO

Combination of Three Lenses, mounted in Tortoise-shell, for pocket, j 5 00

Coddington Lens, f-inch focus, mounted in Silver, . . • 12 50

" |-inch focus, mounted in Aluminium Bronze, . 12 50

" " f-inch focus, mounted in German Silver, . . 8 50

" " £-inch focus, mounted in Gold, . . . . 22 50

" " £-inch focus, mounted in Silver, . , . . 8 50

" '* £-inch focus, mounted in Aluminium Bronze, . 8 50

" £-inch focus, mounted in German Silver, . . 7 00

ACHROMATIC TRIPLETS.

355. Beck's Achromatic Triplet, 1-inch focus, in Silver Case,

356. '" " " 1 " " "

357. " »« " I " " u

358. «• '4 4< 1 4t " M

13 50
12 50
12 50
33 50

68

R. & J. BECK, PHILADELPHIA.

CASES OF MOUNTING MATERIALS.

Xo. PElCfi

360. Collection of Mounting Materials and Dissecting Instruments,

Consisting of Wood-cutting Instrument and Chisel, Instrument for
cutting circles of thin Glass, Glazier's Diamond, Writing Diamond,
Cell-making Instrument, Brass Table and Lamp, Page's Forceps,
Case of Dissecting Instruments, containing 4 Knives, 2 Hooks, 2
Points, 3 pairs of Scissors, 3 pairs of Forceps and Needle- holder,
Valentin's Knife, 1 oz. Thin Glass, 9 dozen Slips, 3 inch by 1 inch,
3 dozen Wooden Slips, 3 dozen Glass Cells, 200 Labels, 5 Capped
Bottles, containing Canada Balsam, Asphalt, Gold-size, Glycerine
and Marine Glue, Bottle of Dean's Medium. 3 Stoppered Bottles
for containing Chloroform, Nitric Acid and Liq. Potassse, . . $100 00

The whole packed in a strong Mahogany Case.

No. 372.

R. & J. BECK, PHILADELPHIA.

69

CASES OP MOUNTING MATERIALS.

No. Price.

361. Collection of Mounting Materials, $40 co

Consisting of Writing Diamond, Cell-making Instrument, Brass
Table and Lamp, Page's Forceps, Case for Dissecting Instruments,
1 oz. Thin Glass, 6 dozen Slips, 3 inch by 1 inch, 3 dozen Wooden
Slips, 2 dozen Glass Cells, 150 Labels, 5 Capped Bottles, containing
Canada Balsam, Asphalt, Gold-size, Glycerine and Marine Glue,
1 Bottle of Deane's Medium.
The whole packed in a strong Mahogany Case.

365. Reagent and Mounting Rack, containing 12 bottles, filled with
various reagents, cements, etc., each provided with a dropping
tube fitted to the cork, and ten test tubes with fittings, . . . 3 CO

SOS. Improved Wood Cutting Machine, with Chisel, packed in Mahog-
any Case, 9 50

369. Page's Wooden Forceps, for holding Glass Slips, when heated, . 50

370. Smith's Mounting Instrument for pressing down the Cover on the

Glass Slips, with a graduated pressure, 3 00

372. Small Air-pump and Receiver, 12 50

CABINETS FOR MICROSCOPIC OBJECTS.

465. Mahogany Cabinet to hold 600 objects, with double glass doors

and improved slide-rests, showing each object clearly when the
drawers are pulled out, and allowing their easy removal, . . 45 00

466. Best Spanish Mahogany Cabinet, with glass panel and deep

drawer at bottom, to hold 1000 objects, 70 00

467. Honduras Mahogany Cabinet, without glass panel or deep

drawer to hold 1000 objects, 55 00

468. Best Spanish Mahogany Cabinet, with glass panel, to hold

750 objects, 50 00

469. Honduras Mahogany Cabinet, without glass panel, to hold 750

objects, 44 CO

470. Best Spanish Mahogany Cabinet, with glass panel, to hold 500

objects, , ... 40 00

471. Honduras Mahoghany Cabinet, without glass panel, to hold 500

objects, 35 CO

In the above Cabinets there are porcelain tablets let into the fronts of the
drawers. The drawers are numbered and the specimens lie flat.

POSTAL BOXES FOR MICROSCOPIC OBJECTS.

482. Card-board Boxes fitted with Racks to hold 12 Objects,
484. Postal Boxes, to take 1 Object,

485.
486.

487.
488.

3

6

12
25

CASES FOR MICROSCOPIC OBJECTS.

489. Portable Horizontal Slide Case, with 12 Trays, holding 12
dozen objects, lying flat, the same as in case No. 472, with a sub-
stantial cover of bookbinder's cloth,

15
6
8
10
12
15

4 00

70

K. & J. BECK, PHILADELPHIA.

CABINET FOR MICROSCOPIC OBJECTS.

No. 466.
One-Fourth Actual Size.

R. &. J. BECK, PHILADELPHIA.

CASES FOR MICROSCOPIC OBJECTS.

71

No. 472.
No. ' PRica.

472. Portable Horizontal Slide Cabinet, in Mahogany, with 12

Trays, to hold 12 doz. Objects, £8 00

473. Portable Horizontal Slide Cabinet, in Mahogany, with 12

Trays, to hold 6 doz. Objects, 5 00

474. Portable Horizontal Slide Cabinet, in Mahogany, with 6

Trays, to hold 3 doz. Objects, 3 00

474*. Portable Horizontal Slide Cabinet, in Pine, with 4 Trays,

to hold 2 doz. Objects, 100

No. 473.

72

K. & J. BECK, PHILADELPHIA.

TABLES, etc.

No 491.

Na

Paice.

491. Revolving Table, especially arranged for Microscopic purposes, in

Walnut or Mahogany, with handsome Leather Top, Gilt Border, §50 00

492. Revolving Table, the same in construction and size as 491, with plain

Eastlake base, and Solid Walnut Top, finished in shellac, . 25 00

493. Revolving Table with Solid Iron Frame, and Walnut Top, 30 inches

in diameter. Very firm and steady, 12 00

No. 495.

495. Walnut-wood Stand, with Leather Top, on Rollers, to carry a
Microscope and Lamp round a Table,

7 50

R. & J. BECK, PHILADELPHIA.

73

HAND MAGNIFIERS, etc.

No.

600.

Oval-shape,

601.

(«

ti

(502.

t<

n

C03.

it

tt

604.

it

tt

• 05.

Long-

shape,

606.

tt

tt

607.

it

it

608.

tt

it

609.

(t

it

615.

ii

ii

616.

tt

it

619.

tt

it

620.

tt

«i

621.

tt

ii

625.

Linen

-prove

(&6.

tt

ti

627.

tt

ti

about 2-in diam.

1

1 1

.

1

it

. .

1

it

. .

1

it

. .

1

it

. ,

1

ii

with dia'm,

2

it

tt tt

3

it

tt tt

2

it

. .

o

tt

. .

3

ti

. .

3

it

* .

2

it

n

i

1*

t

if

tt

3

5

ii

15
16

it

x>

a

5

s

5

ft

3

4

tt

is

it

3

1

tt

tt

ti

% and \ "
Linen-prover, Brass frame with \ or £-in. Open Square,

Nickel-plated, " " ' " .

" \ or £-in. opening ; Achromatic lens,

^RICE.

30

50

60

75,

90

40

60

75

1 00

1 50

65

90

90

1 25

1 25

50

75

1 00

630.
630*
631.
632.
632*
653.
633*
634.
634*
635.
635*
636.
636*
637.
638.
639.

640.
641.

WATCHMAKERS' AND ENGRAVERS' GLASSES, etc.

Watchmakers' Glass of f- , 1-inch, lf-inches diameter, as desired,
" " with two lenses, of different powers .

" " " small lens, high power,

Engravers' " " 2 plano-convex lenses, If-inches diam.,

l< " 1 double " lens, If inches diameter

" " 2 piano " lenses, lf-inches diam.,

" " 1 double " lens, lf-inches diameter,

" - '4 2 piano " lenses, If inches diam.,
" " 1 double " lens, If inches diameter,

" " 2 piano " lenses, 2f-inches diam.,

" " 1 double " lens, 2^-inches diameter,

Seed Microscope, with glass cage for living insects, small size,
, " " " " " " " medium size,

" " " " " " large size, .

Flower " " forceps for living insects, folds in pocket-case,

Three-legged Microscope, Brass frame, 2 plano-convex lenses,

adjustment for focus,

Three-legged Microscope, Rubber frame, 2 plano-convex lenses,

" " Steel frame, 2 plano-convex lenses, ,

50
75
75

1 50
75

2 00

1 00

2 50
1 25

3 00
1 L0

75
1 00

1 50

2 00

7o
1 00
1 25

C0DDINGT0N LENSES.

642. Coddington lens, Brass frame, small size,

643.

tt

644.

tt

645.

ti

(546.

ft

647.

tt

648.

tt

" medium size,

" large size,

German-silver frame, with cover, ....
Silver-plated " " very fine article,

" and engraved, " " "

Gilt " " " u "

1 00

1 50

2 00
2 50

4 00

5 00

6 00

74

K. & J. BECK, PHILADELPHIA.

Nos. 625, 626.

No 601.

No. 615.

Nos. 642-644.

No. 621.

E. & J. BECK, PHILADELPHIA.

75

No. 630.

No. 631.

No. 634.

No. 639.

No. 630*.

Nos. 636, 637.

No. 646.

70

E. & J. BECK, PHILADELPHIA.

THE SCHOOL MICROSCOPE

No. 650.

No. Price.

650. The School Microscope, , §6 oo

This instrument consists of a tubular stem about five inches high, the lower
end of which screws firmly into the lid of the box wherein the instrument
is packed when not in use. To the upper end of this stem the stage is firmly
fixed ; while the lower end carries a concave mirror. Within the tubular stem
is a round pillar having a rack cut into it, against which a pinion works that is
turned by a milled head, and the upper part of this pillar carries a horizontal
arm which bears the lenses, so that by turning the milled head, the arm may
be raised or lowered, and the requisite focal adjustment obtained. Three mag-
nifiers are supplied, and by using them either separately or in combination, a
considerable range of powers, from about five to forty diameters, is obtained. A
condensing lens for opaque objects, a pair of brass forceps and pliers, and an
aquatic box for the examination of objects in water, are also supplied. This
instrument is peculiarly adapted for educational purposes, being fitted in every
particular for the examination of botanical specimens, small insects or parts of
insects, water-fleas, the larger animalcules, and other such objects as young people
may readily collect and examine for themselves; and those who have trained
themselves in the application of it to the study of nature, are well prepared for the

R. & J. BECK, PHILADELPHIA.

t i

advantageous use of the Compound Microscope. But it also affords to the scien-
tific inquirer all that is essential to the pursuit of such investigations as are host
followed out by the concurrent employment of a Simple and a Compound Micr ^-
scope, the former being most fitted for the preparation, and the latter for tud
examination of many kinds of objects.

THE SCHOOL DISSECTING MICROSCOPE.

No. 651.

651. The School Dissecting Microscope, $8 oo

This instrument is the same as The School Microscope, No. 650, -with the
addition of two hand rests, as shown in the illustration, which at once convert
it into a most excellent and convenient Dissecting Microscope. They are at-
tached to the stage by milled heads, and are instantly removed if desired.
The whole, microscope, lenses and hand rests, can be packed in the case, which
measures six by three inches, and two and a quarter inches deep.

The Lenses are of a most excellent quality, the Stand firm and well finished,
and it would seem impossible to improve on this really excellent instrument,
either in compactness, efficiency or cheapness. The accompaniments are trie
aame as those with No. 650.

'8

R. & J. BECK, PHILADELPHIA.

THE EXCELSIOR POCKET AND DISSECTING MICROSCOPE.

No. 652.

652. The Excelsior Microscope, with Three Lenses, $2 75

653. " " with Two Lenses, 2 50

654. Set of three hard rubber Slides, with openings of different kinds,to

serve as linen p rovers, .... .... 25

The construction and method of using this Microscope is very simple, and will
be readily understood from an inspection of the engravings. It consists pri-
marily of a small wooden case, the exact size of that shown in the engraving.
To one end of the lid of this case i; attached one of the ends of the box; and
when the lid is reversed and turned npsicle down, it may be slid into the groove
of the case, and then forms a stand for the lenses and glass stage, as shown in
Fig. 652. The lenses and stage are supported by a steel rod, the lower
end of which is hinged to the lid, so that it may be turned down and lie in
a groove provided for it. When raised into the position shown in the figure, it
is held very securely in place by means of* a button ; and this button also serves
to retain it in the groove when it is turned down. The glass stage, which is fit-
ted into a frame of hard rubber, slides easily on the stem, so as to be readily ad-
justable for focus, while at the same time it may be firmly fixed, by means of a
set-screw, at any desired height, and will then serve as a stage for dissecting
purposes. The frame which holds the lenses fits on the top of the stem. A
mirror is fitted into the case, and is readily adjustable by means of the button
shown on the outside, so that light may be reflected up through the stage when
the objects to be examined are transparent; and when they are to be viewed by
reflected light, there is a dark ground of hard rubber, which is also carried by
the stem, and may be turned under the stage, so as to cut off all transmitted
light. Dissecting needles, with neat handles, fit into appropriate grooves.

R. & J. BECK, PHILADELPHIA.

THE BOYS' COMPOUND MICROSCOPE.

//- - '/'/ gg

ti.m..nmn.uujy.i...,. ii...L.].u.t.„ .j

No. 655. Two-thirds Actual Size.

655. Boys' Compound Microscope, . . §2 50

This instrument is a well-made and substantial one, and well adapted to the
study of objects requiring rather more power than can be conveniently obtained
with a simple microscope. It will show satisfactorily the larger animalculse in
pond- water, the scales from a butterfly's wing, and similar minute objects. The
stand is of polished brass handsomely lacquered, with one eye-piece and one
object-glass magnifying, when combined, about 40 diameters or 1600 times. One
prepared object, two glass slips and a pair of brass forceps, are furnished with
it. and the whole is packed in a neat, polished walnut-wood case.

The Rev. Mr. Wood's little book, " The Common Objects of the Microscope"
(No. 1002 of our Catalogue), will be found a most useful and entertaining adjunct
to the instrument. A copy will be mailed to any address for 50 cents. It con-
tains 400 illustrations, printed in colors.

With each Household Microscope, sold at retail, six interesting objects are
furnished without charge.

80

R. & J. BECK, PHILADELPHIA.

THE UNIVERSAL HOUSEHOLD MICROSCOPE.

No. 660.
One-half Actual Size.

No. Price.

660. The Universal Household Microscope, $5 oo

There are a number of Microscopes under this name in the market, and in
adding ours to the list, we have endeavored to add to their efficiency and con-
venience, whilst somewhat reducing the cost.

The Stand is ten inches in height, with hinged joint, allowing it to be inclined
to any angle for convenience of observation. The base is of cast iron, the design
forming the monogram, R. & J. B., handsomely bronzed, the compound body
of finely lacquered brass, with draw-tube for increasing the power. The object-
glass is of three powers, usable separately or combined, magnifying from about
20 to 100 diameters, or, in popular terms, from 400 to 10,000 times. The markings
upon the scales of butterfly's wings, and most animalcules in pond-water are
very well shown by these glasses. A pair of brass forceps, two glass slips, and
one prepared object accompany it, the whole contained in a neat and strong
walnut-wood case.

661. The Universal Household Microscope, the same as 660, with

an Achromatic Object-glass of three powers, in place of the one
furnished with 660, magnifying from 30 to 150 diameters, with ex-
cellent definition, entirely free from color, ..... 8 00

R. & J. BECK, PHILADELPHIA.

THE UNIVERSAL HOUSEHOLD MICROSCOPE.

81

No.

No. 663.
One-half Actual Size.

Prick.

663, The Universal. Household Microscope, with rack and pinion
adjustment of focus, a condensing lens, for the illumination of
opaque objects, and an Achromatic object-glass (Triplet) giving
powers from about 30 to 250 diameters. The same fittings accom-
pany it as are furnished with No. 660, and the whole is packed in a
handsome French polished Mahogany case, ..... $12 00

ACHROMATIC OBJECTIVES. (French Manufacture).

These object-glasses are all triple combinations excepting the first, which is a
doublet; and are really well corrected lenses, giving a clear, well-lighted field
with excellent definition. They all have the French Screw the same as that of No.
663, but can be fitted with the Society Screw for an additional cost of 75 cents each.

764. Achromatic Objective No. 0, 1-inch, doublet, . . . . . 2 50

765.

766.
767.
768.
769.
770.

1,1

triplet,

4
5
6,4

i

> '8"
1

> Iff

» 15

3 00

3 50

4 00

5 00
7 00

10 00

82 R- & J- BECK, PHILADELPHIA.

DISSECTING AND MOUNTING INSTRUMENTS AND MATERIALS,

No. 781.

No.

No. 782.

No. 802.

781. Spring Compressor, Nickel-plated, per doz.,

782. " « Wood, per doz.,

Price.
75

25

No. 785.

No. 786.

No. 786*.

783. Forceps, brass, 3 inches long,

784. " Quekett's for taking objects ont of deep bottles,

785. " Bull-nose,

786. " Cutting,

786*. " opening by pressure, ....

787. " Steel Nickel -plated, straight, 4 inches long,

788. " " " curved, 4 "

789. " " " " 4 "

790. " " " straight, 4 "

791. Scissors for dissecting, straight blades, very delicate, .

792. " " blades curved on the flat,

793. " " elbow blades, ....

794. " " " " very strong,

795. " " with spring, exceedingly delicate,

796. Needle-holder, for Dissecting Needles. Fig. 1, .

797. " for dissecting, straight point, ebony handle, .

798. " " " hook " " ' •'♦
798*. " hook for dissecting double points. Fig. 2,
798*-*. " " " triple " "3,

799. Knives, for dissecting, Figs. 5 to 18, each,

very delicate,

25
50
00
50
00
00
00
50
50
50
50
50
25

6 00
75
15
15
75

1 00
75

R. & J. BECK, PHILADELPHIA.

83

No. 789. No. 790.

No. 701. No. 793.

No. 792.

No. 803.

1. 2. 3. 5. 6. 7^ 8.

9. 10. 11. 12. 13. 14. 15. 16. 17. 18.
Nos. 796-99.

84 R. & J. BECK, PHILADELPHIA.

No. Price.

BOO. Case of Dissecting- Instruments, containing 1 pair forceps (78S),
1 pair scissors (793), 2 dissecting knives (799), 2 needle-holders
(796), with needles, $7 50

801. Case of Dissecting Instruments, containing 1 pair forceps (787),

1 pair ditto (789), 1 pair scissors (792), 1 pair ditto (793), 3 dissecting
knives (799), 2 needle-holders (796), with needles, 1 Valentine's
knife (803), 15 00

802. Dr. Ranvier's " Necessaire," 3 5u

This indispensable little piece of apparatus, which is in use in all
the Hospitals of Paris, and by most Microscopists there, consists
of a circular base of polished wood, in which are arranged six re-
pgent bottles, with ground capillary-tube stoppers, the whole
covered with a low bell-glass, to exclude dust.

803. Knife, Valentine's, for cutting sections of soft tissues, . . 6 50

Nos. 804-806.

804. Knife, for use with section cutters, Nos. 808 to 811, in Morocco case,

805. Knife, for use with section cutters, heavy blade, in Morocco case,
These knives are made specially for us, and are guaranteed to be of

the very first quality. Each is ground fiat on one side and hollow
on the other, and can be furnished to cut toward or from the
operator as desired.

4 00

5 50

Nos. 807-809.

807. Dr. Seiler's Section-knife and Carrier, adapted to any Micro-

tome of the style of 808* or 809. By use of this the largest and
thinnest sections, absolutely even in thickness, may be cut, . 13 50

807* Dr. Seiler's Section-knife and Carrier, for use with No. 810

in both its forms, 15 00

808. Section Cutter, Dr. Ranvier's pattern, with glass top, and binding

screw for holding wood and other hard substances, . . . . 7 00
808* Section Cutter, the same as No. 808, with the addition of a clamp

for fastening to table, 8 00

809. Section Cutter, Army Medical Museum pattern, with glass top,

and clamp for fastening to table, 10 00

B. & J. BECK, PHILADELPHIA.

80

No. 808.

No. 808*

Nos. 813-14*.

86

R. & J. BECK, PHILADELPHIA.

No. 810.

No.

810. Section Cutter, (Mr. Walmsley's adaptation of Dr. Bevan Lewis's
Ether Spray Microtome). Complete with Atomizer,
This instrument, now largely in use by our leading Histologists,
and by the Medical Department of the Army, is confidently
recommended as the most complete and perfect Microtome yet
produced. To the excellent Section Instrument, of the Army
Medical Museum pattern, jSTo. 809, a second table, with glass top,
is added, through which a brass-topped tube, with Condensing
Chamber beneath, is advanced by the same Micrometer screw.
Some thickened gum-water being put upon the top of this tube,
a piece of tissue, say a portion of spinal column from a freshly-
killed animal, may be placed in it, and the nozzle of the freezing
Atomizer having been introduced into the tube beneath, the
tissue will be solidly frozen in from one to three minutes. Ether
may be used, but Rhigolene is much better (we can supply it, if
desired) ; a considerable portion of it will be condensed in the
chamber, and can be drawn off by the tube, shown in the illus-
tration, for further use. The Knife should be kept cold by being
placed on a block of ice before using. Full directions for use
accompany each instrument. If the purchaser already has a
freezing Atomizer, the Microtome may be purchased without it
for §18.00. This Microtome as well as 809 is made in two sizes,
with tubes of 1 inch and IV inches diameter. In ordering please

Price.

#20 00

state which size is desired.

R. & J. BECK, PHILADELPHIA.

87

No. 810*.

No. PRICE.

810*. Taylor's Freezing Microtome, Complete with Rubber Tubing, $16.00

This instrument, the device of Mr. Thomas Taylor, Microscopist of the Depart-
ment of Agriculture, at Washington {and by him patented), is designed to effect
the rapid freezing of tissues for sectioning, without the fatigue or expense attend-
ant upon the use of an atomizer for the same purpose. It is extremely simple
in construction, cannot get out of order, and is always ready for use wherever
a block of ice and some salt can be procured.

Its general design is the same as that of the preceding instrument No. 810.
As in that form, the Microtome is a double one, equally adapted to imbedding
or freezing. The lower, or imbedding instrument is the same as that of our No.
809, to which is added a second table precisely the same as in No. 810, through
which a brass topped Chamber is advanced by Che same Micrometer screw. To
this Chamber are attached supply and discharge tubes ; the latter being slightly
smaller than the former, and prolonged inside the chamber to within Jth of an
inch of its top, insures the same being kept constantly full of the freezing fluid.
The latter is the product of the melting of chopped or shaved ice and coarse salt,
and is supplied to the large tube of the freezing chamber, by means of a syphon
rubber tube leading to the vessel containing the same. The discharge is by
means of another rubber tube, and the flow can be regulated at pleasure by nip-
ping the discharge tube with an ordinary spring clothes pin.

Having arranged with Mr. Taylor for the manufacture and sale of this Micro-
tone, we are prepared to furnish it made at our own works and guaranteed to be
of the best workmanship and finish. Mr. Taylor's device is simply the method
of freezing by the flow of melting ice through the chamber. All other portions
of the instrument are precisely the same as those in our Microtone No. 810, so
well and favorably known to Microscopists everywhere.

88

R. & J. BECK, PHILADELPHIA.

No.

No. 811..

Price.

811. Section Cutter (Rutherford's Microtome), Army Medical Mu-
seum pattern, large size, with ice-box for freezing, . . . $15 00

No. 812*.

812. Section Cutter, pattern of M. Rivet, in wood, with knife, . . 7 50
812*. " " " " " in brass, with Micrometer 15 00

Screw and Knife,

813. Injecting Syringe, of brass, finest quality, i-oz. capacity, with four

pipes and stop-cock, in fine Morocco case,

814. Injecting Syringe, the same as 813, of 1-oz. capacity, . . . 10 00
814*. " « " " 2-oz. " ... 12 00

815. Turn-Table, with Walmsley's centering adjustment, . . 4 00

R. & J. BECK, PHILADELPHIA.

89

No. 812.

No. 809.

No. 816.

00

P. & J. BECK, PHILADELPHIA.

No. 815.

No. 818*

No. 874.

No. 875.

R. & J. BECK, PHILADELPHIA.

91

No.

816. Turn-Table, Shadbolt's

817. " " Sidle's "Congress," self-centering, .

818. "■ Cox's improved self-centering, for all Slides,

818i:". " " Beck's "New Spring," self-centering for all slides,

and with clamp for attaching to edge of a table or shelf; recom-
mended as being the most perfect Turn-table as yet produced,

Price.
3 00
6 50
6 CO

7 00

No. 819.
819. Brass Table, with folding legs and lamp, for mounting with

balsam, .

819*.Brass Table and Lamp, small size,

2 50
1 50

No. 876.

02

No.
820.

821.
822.
823.
824.
825.

826.

827.

R. & J. BECK, PHILADELPHIA.

Price.

Flatted Crown Glass Slips, Chance's Best, 3x1 inch, cut edges,
per dozen, 15 cents, per gross, $1 75

Flatted Crown Glass Slips, Chance's Best, 3x1 inch, smoothed
edges, per dozen, 30 cents, per gross, . ... 3 00

Plate Glass Slips, Chance's Patent, 3x1 inch, cut edges, per
dozen, 30 cents, per gross, 3 00

Plate Glass Slips, Chance's Patent, 3x1 inch, smoothed edges,
per dozen, 40 cents, per gross, 4 50

Plate Glass Slips, Chance's Patent, 3x1 inch, extra thin, smooth-
ed edges, per dozen, 55 cents, per gross, 5 00

Wooden Slips, 3x1 inch, with hole in centre, used in mounting ob-
jects between thin glass, or opaque, per dozen, .... 25

Glass Slips, with Hollow, 3x1 inch, smooth edges, per dozen, . I 50

Glass Slips, 3x1 inch, smooth edges, with cells of various sizes,
shapes and depths, attached by marine glue, ready for use, per
dozen, 2 50

828.
829.

830.

830*
831.
832.
833.
835.
836.
837.
838.
839.
840.
841.
842.
843.
844.
845.
847.
848.
849.
849*
850.
851.

No. 828.

Glass CELLS,of various sizes, shapes and depths, per dozen,
Block- Tin Cells, of various sizes and depths, for fluid and balsam
mountings, per dozen,

dry and

Hard-Rubber Cells, of various sizes and depths, for

opaque mountings, per dozen,

.Atwood's Hard-Rttbber Cells, per dozen,
Thin Glass, in sheets, No. 3, -£$ to y^, per oz.,

" " " " No. 1, j\-q to ^j, or thinner, per oz.,

" " " squares, No. 3, per dozen, 18 cents, "

" " " " No. 2, " 20 " "

" " " " No. 1, " 25 "

" " in circles, No. 3, per dozen, 20 cents, per oz.,

" " " " No. 2, " 25 " "

" " " " No. 1, " 30 " "

Watch Glasses, all sizes, each 7 cents, per dozen,

Dipping and Dropping Tubes, each,

Pippets, with bulb,

Test Tubes, all sizes, each, 3 to 8 cents, per dozen,

Bell Glass, for preserving objects from dust during preparation,

Canada Balsam, pure, in collapsible tubes,

" " in chloroform, requires no heat, per bottle,

in Benzole, " " "

" in absolute alcohol,

*Damar " " "

Glycerine, pure, ........ ^

1 00

50

30

15

30

75

1 00

1 50

1 25

2 25

2 75

2 25

2 75

3 75

75

10

25

to 75

50

25

50

50

50

50

25

R. & J. BECX, PHILADELPHIA. 93

No. Prick

852. Glycerine, Camphorated, for mounting fresh- water algse, per bottle, . 25

853. " Jelly, 50

854. Deane's Medium, 35

855. Farrant's Medium, 60

856. Absolute Alcohol, (Dr. Squibb's,) 25

857. Benzole, Pure, 25

858. Brunswick Black, ' 25

859. Asphalte, . . 25

8C>0. Gold-Size . 25

861.

861*

862.

863.

863*

864.

865.

865*

866.

867.

868.

No. 869. No. 847.

Marine Glue, ;

.Liquid Marine Glue

Oil of Cloves,

Bell's Cement,

Brown's Transparent Rubber Cement, .

White Zinc Cement,

Punches, various sizes, \ inch to 1 inch,
Improved Punch for cutting cells from Sheet Wax,
Instrument for cutting circles of thin glass, in case,

Glaziers' Diamonds, from

Writing Diamonds, best quality made, each,

No. 861.
per bottle,

35
50
50
50
35
50

each, 50 to 1 50
1 50
10 00
4 CO to 10 00
3 50

No. 868.

94

IL & J. BECK, PHILADELPHIA.

No. 872.

No. 872.*

No. 872.

PRICR

50
25
30
00
50
00

No.

869. Capped Bottles for containing fluid used in mounting objects, each,

870. Dropping " with glass bulb stopper, "

871. " " " rubber top " «

872. Small Collecting Bottles, per dozen, 30 to

;872.*Capillary Bottles, each,

€73. Wright's Diatom Collecting Bottle, complete in case,

€74. Mounting Cabinet, as arranged by Mr. Walmsley ; containing 6

compressors, wood (782), 6 ditto Nickel-Plated (781), Steel Forceps
(788), Scissors (793), Knife (799), Needles (797 and 798), Turn-table
<(816), Brass Table and Lamp (819*), i gross slips (821), £ oz. assorted
Squares and Circles (836 and 839), 1 doz. Hard-Rubber Cells (830),
1 doz. Block-tin Cells (829), 3 Watch-glasses (841), Dropping Tube
(842), Tube of Balsam (847), Damar (850) or Balsam (849), Glycerine
<851), Glycerine Jelly (853), Hsematoxylon (877), Brunswick Black
(858), Gold-size (860), Oil of Cloves (862), White Zinc Cement (864),
Dropping-bottle (871), 1 Nest of Saucers (875), wide-mouth Glass Jar
for Solutions, 2 Camel' s-Hair Brushes in long handles. The whole
packed in a polished mahogany cabinet with lock, .... I
Porcelain Saucers, in nests of 5 with cover, all fitting, dust tight.
The most useful of all articles in staining tissues and soaking in
oil of cloves, (two sizes), 60 and

Hot-water Drying Case, for drying tissues and hardening Balsam
mountings, made entirely of heavy Planished Copper, will harden
twelve dozen specimens at once, .... ... 15 00

875.

5 Cl

80

STAINING AND INJECTING FLUIDS, Etc.

877.
878.
879.
880.
881.
882.
883.
834.
885.
886.
887.
888.
889.

per bottle,

u u

Hsematoxylon,, ..

Ammonia Carmine, . . •

Borax " . . .

Carmine &ed, -

Dr. Woodward's Violet Carmine,

Methyl Aniline, Green,

Magenta " &ed,

Blue " •

Eosin, ......

Osmic Acid, ^ oz. in glass capsule,
Picro Carmine, ....

Sulphindigotate of Soda, (Dr. Seller's,)
Carmine Injecting, Gelatine, (Dr. Seller's,)

One oz. of this Gelatine dissolved in ten oz. of distilled water forms

an admirable Injecting Fluid.

per bottle,

oz.

25
25
25
35

25
25
25
25
25

3 00
25
25

1 00

R. & J. BECK, PHILADELPHIA, 95

LABELS, etc. FOR MICROSCOPIC 0BJECT&

&f2

894

No.

890. Adhesive Labels, Plain White, Hound or Oval, . . per box,

891. " " Assorted Colors, Square, neatly bordered, " 100,

892. " Fronts for covering slides, handsome gold design " 100,

893. " " for covering slides, handsome bronze design " 100,

894. Backs for covering slides, " 100,

Backs or fronts if with holes punched, extra, . . . " 100,

HOLMAN'S LIFE AND CURRENT SLIDES.

Price.

10

25
50
W
10
16

No. 895.

These very useful and ingenious accessories to the Microscope are attracting
great attention among scientific men everywhere, and have received the strongest
commendations from Medical and other Scientific Journals at home and abroad.
By an arrangement with the inventor we are enabled to supply them to our
customers of the most perfect quality, each one having passed through Mr.
Holman's hands before being delivered to us.

96

R. & J. BECK, PHILADELPHIA.

895. Holman's Life Slide, with Cover m a neat Box, $1 50

The Life Slide consists of a plate of thick glass 3 X 1-inch, with a deep oval
cavity ground in its centre, to contain the mass of material under observation.
Around the margin of this oval cavity is a polished bevel, and from the bevel
extends a small cut, the object of which is to afford an abundance of fresh air to
the living things within. It is found upon inclosing the animalcule, etc., that
they will invariably seek the edge of the pool in which they are confined, and
the beveled edge permits the observer to take advantage of this disposition ; for
when beneath it, the objects are within the range of the highest powers.

The Life /Slide is constructed to retain the greatest quantity of material under
the smallest cover glass, and is designed to be used with the highest powers of
the Microscope for studying the Bacteria, Vibriones and other low forms of life.
For studying the circulation of the blood in the tail of the Tadpole, it is the most
perfect contrivance imaginable. The deep oval cavity will contain the body of
a small Tadpole, whilst the tail lies extended in the beveled portion, and may
be examined with the highest powers. Another very important feature in the
device is the fact that a preparation may be kept with it for days or weeks
together without losing vitality, owing to the simple arrangement for supplying
fresh air.

No. 896.

896. Holman's Current Slide, with Cover, in a neat Box, ... $1 50

The Current /Slide, consists of a slip of plate-glass 3x1 inch, in which two oval
concave cells are ground, there being a space of ^ inch left between the cells.
These cells, which are about \ inch in diameter and as deep as the glass will
permit — say ■£% inch deep — are united by a very shallow channel somewhat
below the centre of the two cells, so that with cells placed ^ inoh apart, the
channel is about ^ inch long. Both the cells and channel are polished. If a
few drops of blood be placed in the cells, and a cover of thin glass be pressed
down, some of the blood, finding its way between the surfaces in contact, will
dry, and act as a cement to hold the fluid blood in the cells in place. The
quantity of blood being insufficient to fill the cells, a considerable amount of air
becomes imprisoned with the blood, and the expansion of the air in either cell
will drive the blood through the channel into the adjacent cell, and in the shal-
low channel it is presented under the most favorable condition for examination.
By holding the top of the finger near one or the other ^Is, the heat is enough
to cause the expansion and a consequent more or less rapid flow of the fluid
through the channel. This flow may be arrested, or continued and reversed at
will, by change of the position of the finger, so that any particles floating in the
liquid can pass in succession across the field, but can be arrested and examined
with ease at will.

So sensitive is the apparatus, that even with the highest powers, a corpuscle,
granule or cell in the field of view, may be leisurely turned over and over in
any desired position, thus affording an unequaled means of obserration and
study to the microscopist ; and while the eye is examining at leisure the

R. & J. BECK, PHILADELPHIA.

97

behavior of the objects beneath it, the mind is charmed with the simplicity of tha
means by which their motions are controlled.

Blood or other fluid inclosed in the cells remains in good condition for exami-
nation for several days, and changes undergoing in the fluid can be examined.

No. 897.

897. Ho f man's Syphon Slide, complete, with Flexible Tubes and Glass

Cover, but without Bottles, $4 00

This is a modification of the " Life" and " Current" slides, whereby living
objects of suitable size and habits can be retained under observation uninter-
ruptedly for days or even weeks. A current of water, or other fluid, is made to
flow continuously through the chamber containing the object, so that the pro-
cesses of respiration, circulation, digestion and nutrition, the phenomena of
inflammation, and the effects of some classes of poisons, may be studied at
leisure and under perfectly natural or entirely controllable conditions. The
habits of life of small aquatic animals are similarly brought within reach of our
observations. For use with the Magic Lantern, in projecting the images of
living objects upon the screen, this apparatus is absolutely perfect — the flow of
fresh water through the chamber being so constant that its inmates are entirely
tree from inconvenience during the most protracted exhibition.

The following description of the Syphon Slide will render its construction
and use quite clear. In a slip of thick plate glass, a chamber is excavated simi-
lar to that in the Life Slide. In each end of this chamber are fine perforations,
too small to permit the escape of the animal under view, but sufficient to main-
tain a flow of water. These openings merge into tubular mouths, to each of
which is attached a tightly-fitting elastic tube: one of these communicates with
the reservoir of water, whilst the other acts as an escape-conduit. The position of
the slide, when in use, must be slightly above the level of the reservoir, while
the escape-tube must rest below the same, thus insuring a veritable syphon
action in the apparatus ; a constant flow of water being secured in connection
with the required atmospheric pressure for the retention of the cover on the
slide. It is not necessary to have bottles specially fitted for use with this appa-
ratus ; any vessel capable of holding water will answer, it being only necesary
to insert the end of one tube in the reservoir, and by gently sucking at the end
of the other establish a flow of the water, which will continue so long as the
reservoir contains any.

98 E. & J. BECK, PHILADELPHIA.

898. Holman's Syphon Animalcule Cage, complete, with flexible tubes, #4 50

No. 898.

This new device of Mr. Holman's consists simply of an Animalcule Cage of the
largest size, (No. 167 of this Catalogue,) to which is attached a pair of flexible
rubber tubes, as shown in the illustration, which act as a syphon, and give the
device a special value as a moist chamber for studying growing fungi and other
minute and delicate plants without disturbing them.

No. 899.

899. Holman's New Parallel Compressor, $6 oo

This Compressor is arranged differently from all other devices of the kind in
having the thin covering-glass fixed and immovable, whilst compression of the
cell-contents is effected by moving the lower plate of glass, which is done by
means of a milled-head and spiral spring. The lower plate is so arranged as to
swing out laterally from beneath the cover, thus allowing both to be readily
cleansed.

900. Beck's New Hard Rubber Zoophyte Trough, . . . . . $3 oo

This new Trough is so neat, convenient and free from faults that it cannot fail
to be used with pleasure. Two plates of glass are separated by a half ring of soft
rubber (of any desired thickness), and clamped together by two plates of hard
rubber held in position by three binding screws, and cutaway to show the objects,
as in the.illustration. Any thickness of glass can be used with this device, and
the same can be easily taken out for cleansing, or replaced if broken, and the
thickness of the cell can be varied indefinitely by using different thicknesses of
sheet, rubber between the glasses.

R. & J. BECK, PHILADELPHIA.

99

MEDIAN'S MICROSCOPE ILLUMINATOR.

LAMP WHEN
PACKED IN CASE.

EXTERIOR OF
CASE.

925. LAMP.

No.

Price.

$15 00

925. Fiddian's Microscope Illuminator, nickel plated,

This very convenient and useful Lamp has been designed to combine the
qualities of other Microscope Lamps, together with greater portability, the
whole fitting into a brass tubular box, the exterior of which is covered with
morocco leather, the lid forming the stand of the Lamp. The metallic chimney
being telescopic, occupies a very small compass ; the condenser fits into the cell
in front. The reservoir is of brass, and will contain sufficient petroleum for six
hours' consumption. The entire Lamp fitting into the case from the top, escape
of the oil is prevented.

In trimming the Lamp care should be taken that the wick is perfectly dry,

and the petroleum of good quality; also that none of the oil gets upon the

metallic chimney or reservoir, or a bad smell will' be given off until the oil is

burnt away.

In using the Lamp it will be found convenient to slightly incline it, so as to

bring the broad surface of the flame more parallel with the

surface of the mirror of the Microscope.

When it is necessary to re-line the chimney, screw off the
sliding portion, wash out the old lining, and recoat it with
superfine Plaster of Paris. When dry it will be found ready
for use — a few minutes will be found sufficient to do this.

/Size of Case:— Height, 6 inches; Diameter 3 inches.

No.
929.

929.

930.
931.

Beck's Microscope Lamp. This very portable,
simple, and cheap lamp, is arranged to carry
the flame at any desired height above the table,
thus adapting it to the use of all sizes of Micro-
scopes. The shade is of paper, enamelled green
on the exterior, affording full protection to the
eyes, and emitting no heat. The base is heavy,
and the lamp perfectly steady at any height, .

German Student Lamp. Brass,

" Nickel-plated,

Price,

6 50

5 00

6 CO

100 It. & J. BECK, PHILADELPHIA.

MOLLER'S DIATOMACEEN AND OTHER TYPEN PLATTES.

951. Moller's Diatomaceen Typen Platte, No. 1, is a slide of the usual size-
three inches by one inch — comprising about 500 Diatoms (correctly 392 distinct
species and varieties), being acknowledged types of Seventeen Genera of the
Order Diatomacese. The shells are arranged in four quadrangles, each formed
of six lines, and each line containing about sixteen species, presenting a figure
of the following form :

II

1..... 1.

2 2.

3 3

4 4.

5 5.

6 6.

III. IV.

1 1

2 2

3 3

4 4

5 5

6 6

Easy reference to each member is afforded by an accompanying Printed Cata-
logue, by which the name of any individual Diatom on the slide may be learned ;
or any name in the Catalogue as easily identified with its corresponding shell
on the slide.
The classification is that of Herrn A. Grunow, of Berndorf, near Wien.
To the name of each Diatom is appended : its nature, whether fossil or recent;
its origin, whether marine or from brackish or fresh water; its geographical
locality, with the name of the naturalist who assigned its nomenclature.

Price, in morrocco case, with bound Catalogue, $30 00

952. Moller's Diatomaceen Typen Platte, No. 2, is a smaller collection of
One Hundred Diatoms, by the same artist, arranged on the same
plan in one quadrangle, accompanied by a printed Catalogue, and
quite equal in quality to the larger collection. Price, . . . 12 00
£53. Moller's Diatomaceen Typen Platte, No. 3, is similar to 952, but
has the name of each Diatom photographed beneath it, so that
specimen and name can be seen at one view. Price, . . . 13 50

954. Moller's Diatomaceen Probe Platte is a collection of 20 Diatoms,
by the same artist, arranged in a single line, on a slide of the usual
size — 3x1 inch — in Balsam, and graduated according to their value
as test objects. In a neat morocco leather case, with descriptive

list. Price, 6 00

955. Moller's Diatomaceen Probe Platte, the same as 954, but mouuted

dry. Price, . 7 50

956. Moller's Typen Platte of the Holothuridae, containing 34 species
mounted on a slide of usual size — 3x1 inch. In morocco case, with
descriptive Catalogue, Price 1500

957. Moller's Typen Platte of the Echinoidea, on slide 3x1 inch. In
morocco case, with Catalogue. Price, . . . , . . 7 50

R. & J. BECK, PHILADELPHIA. 101

FASOLDTS' BANDS OF TEST LINES.

These superb rulings are believed to be superior to any ever made, and since
the death of M. Nobert, are the only ones that can be depended upon for accu-
racy and uniformity of spacing. They are ruled on thin glass and mounted in
brass frames 3x1 inches.

No. PRICE.

97f>. 18 Bands, 5,000 to 120,000 to the inch, $ 15 00

976. 27 " 5,000 " 250,000 " " " ..... 25 00

977. 30 " 5,000 " 500,000 " " " . . . . . 50 00

978. 41 •« 5,000 " 1,000,000 " " " . . . ' . 100 ( 0
980. 19 " 100 " 6,000 " " Millimetre, .... 18 00

DOUBLE STAINED VEGETABLE TISSUES.

These very beautiful and instructive preparations, by our Mr. Walmsley,
comprise a great variety of Tissues, Sections of Stems, Roots, Leaves, Seeds,
etc., stained by his own processes, and mounted in the best manner. They will
be found far superior to any similar preparations ever before offered for sale, and
are worthy of a place in the Cabinet of every Microscopist. They range in price
from 50 cents to $1.00, according to variety, difficulty of preparation, and per-
fection of staining.

SERIES OF POPULAR OBJECTS.

30 cents each, $3.00 per dozen, $6.00 for two dozen in box.
Six dozen, in handsome mahogany case with twelve trays and lock, . $20 00
In order to meet the demand for objects of a popular character, at very low
prices, we have prepared under Mr. Walmsley's supervision, a very large vari-
ety of beautiful, interesting and valuable subjects, at the above cheap rates.
These comprise about one hundred varieties of Diatoms, many species of
Algse, Marine and Fresh-water ; Foramnifera, Polycistina, Spicules of Synapta,
Gorgonia and Sponges, insect parts in immense variet}*- — opaque and transpar-
ent— some whole insects, vegetable preparations of every kind, including some
Double Stainings, in short, a wonderful variety of objects deservedly popular.
They are all clean, neatly mounted and correctly named, and though not selected
as those named in the foregoing lists, many of them will be found fully equal
in all particulars to the more expensive ones. An assortment will be sent on
selection, the same as the others.

SERIES OF HOUSEHOLD OBJECTS.

Slides 2fx| inch, 18 cents each. $2.00 per dozen.

This series of objects comprises most ot the subjects named in the Popular
Series, mounted on small slides of the French size, and are especially adapted
to examination with the smaller and cheaper Microscopes. They are all good
and clean, and being exceedingly cheap, a considerable assortment can be had
for very little outlay. Every young person will appreciate their beauty and the
instruction to be derived from their careful examination.

Our Complete Classified list of Objects in every Department of Natural Science,
is now issued in a separate pamphlet of 32 pages, which will be mailed on applica-
tion, to any address in the world, free.

102 R. & J. BECK, PHILADELPHIA.

DEMONSTRATION LENSES.

No. Price.

1206, Demonstration Lenses. A set of six, If inches diameter, showing
the forms of the various kinds of lenses, viz. : Double Convex,
Double Concave, Piano-Convex, Piano-Concave, Meniscus Con-
vex, and Meniscus Concave. Per set, . . . . . $2 50

COSMORAMA LENSES.

1209. Double or Piano-Convex Lens, 8 inches diameter, and either 30, 36,

48 or 72 inches focus, each, 4 00

1210. Double or Piano-Convex Lens, 7 inches diameter, same foci as

1209, each, 3 00

1211. Double or Piano-Convex Lens, 6 inches diameter, of either 24, 30,

36, 48 or 72 inches focus, each, 2 50

1212. Double or Piano-Convex Lens, 5 inches diameter, of either 18, 20,

24, 30, 36, 48 or 72 inches focus, each, . . . . . . 1 75

1213. Double or Piano-Convex Lens, 4 inches diameter, of either 12, li,

16, 18, 20, 24, 30, 36, 48 or 72 inches focus, each, . . . . 1 25

1214. Double or Piano-Convex Lens, 3 inches diameter, any focus 6 to 36

inches, each, . 75

1215. Double or Piano-Convex Lens, 2 inches diameter, any focus 6 to 36

inches, each, 60

1216. Double or Piano-Convex Lens, li inches diameter, any focus 5 to

48 inches, each, 58

MICROSCOPE AND TELESCOPE LENSES.

1217. Double or Piano-Convex Lens, 1 inch diameter, 2 inches focus, 75

1218. " " " I " li

1219. " " " I- " U

1220. " " " i . " 1

1221. " " "I "I

1222. " " " i " i
1225. " " " & " i
.1224. " " " i " I

7o
75
75
75
75
75
75

ACHROMATIC OBJECT-GLASSES for SPY-GLASSES and TELESCOPES.

1225. Achromatic Object-Glass, li inches diameter, 18 to 30 inches focus, 2 00

1226. " " II " " 18 to 30 " " 3 50

1227. " " 2 " " 18 to 30 " " 4 00

1228. " " extra fine finish, 2 in. diam., 36 in. focus, 7 00

1229. " " " " 2\ " 44 " 10 CO

1230. " " " " 3 " 48 " 22 50

1231. " " " " 3^ " 54 " 45 00

1232. " " " " 4 " 60 " 80 00

E. & J. BECK, PHILADELPHIA. 103

PRISMS.

No. Prick.

1235. Solid Flint Glass Prisms, 3 inches long, each, . . , . $ 50

1236. " " 4 " " 60

1237. " " 5 " " 80

1238. " " 6 " " 1 00

1239. " " 7 " " 1 25

1240. " " 8 " "...... 1 50

READING AND PICTURE GLASSES.

1324. Reading Glass, oxidized metal frame, double convex lens, 2 in. diam., 75

1325. Reading Glass, oxidized metal frame, double convex lens, 2J inches

diameter, 1 00

1327. Reading Glass, oxidized metal frame, double convex lens, 3£ inches

diameter, 1 75

1329. Reading Glass, oxidized metal frame, double convex lens, 4} inches

diameter, . . 3 00

1330. Reading Glass, gilt metal frame, ivory handle, one double convex

lens, 2£ inches diameter, . . . 2 25

1331. Reading Glass, gilt metal frame, ivory handle, double convex lens,

4 inches diameter, 4 00

1332. Reading Glass, black metal frame, wood handle, double convex

lens, 3 inches long by 1£ inches wide, 1 25

1333. Reading Glass, black metal frame, wood handle, double convex

lens, 4 inches long by 2 inches wide, 2 00

1334. Picture Glasses, wood frame and handle, double convex lens 5

inches diameter, 4 00

1335. Picture Glasses, wood frame and handle, double convex lens 6

inches diameter, 5 00

DOUBLE CYLINDRICAL READING GLASSES.

These entirely new and very superior Reading Glasses are made of a double
cylindrical lens, with its axes crossing at right angles, giving an entirely flat
field free from chromatic or spherical aberration, reading to the extreme
edge. Their great superiority to the old form of double convex lenses is appa-
rent at a glance.

1340. Reading Glass, double cylindrical, German silver frame, black

handle, 2x3 inches, $2 50

1341. Reading Glass, double cylindrical, German silver frame, black

handle, 2T3^x3i inches, 3 50

1342. Reading Glass, double cylindrical, German silver frame, black

handle, 2T5^x3| inches, 4 50

1343. Reading Glass, double cylindrical, German silver frame, black

handle, 2|x4| inches, 5 50

1344. Reading Glass, double cylindrical, German silver frame, black

handle, 2£x4£ inches, 6 50

1345. Reading Glass, double cylindrical, German silver frame, ivory

handle, 2x3 inches, 4 00

1346. Reading Glass, double cylindrical, German silver frame, ivory

handle, 2T3^x3i inches, . . 5 00

1347. Reading Glass, double cylindrical, German silver frame, ivory

handle, 2^x32 inches, ..600

104

R. & J. BECK, PHILADELPHIA.

Nos. 1324 to 1333.

R. & J. BECK, PHILADELPHIA.

105

Nos. 1340 to 1350.

106 R. & J. BECK, PHILADELPHIA.

No- Price.

1348. Reading Glass, double cylindrical, gilt frame, ivory handle,

2^x31 inches, §6 00

1349. Reading Glass, double cylindrical, gilt frame, ivory handle,

2|x4i inches, 9 50

1350. Reading Glass, double cylindrical, gilt frame, ivory handle,

23x4i inches, 10 50

ACHROMATIC SPY-GLASSES OR TELESCOPES.

No. 1375.

No. 1381.

No. 1365.

No. 1390.

1375. Achromatic Spy-glass, with wood body, and three draws, 15 inches

long when drawn out, 6 inches long when shut up ; object-glass

1 inch in diameter. Power 15 times, §2 50

1376. Achromatic Spy-glass, with wood body, and three draws, 16 inches

long when drawn out, 6 inches long when shut up ; object-glass

1£ inches in diameter. Power 20 times, 3 50

1377. Achromatic Spy -glass, with wood body, and three draws, 23 inches

long when drawn out, 8 inches long when shut up ; object-glass

If inches in diameter. Power 25 times, 5 00

1378. Achromatic Spy-glass, with wood body, and three draws, 30 inches

long when drawn out, 10 inches long when shut up ; object-glass

1& inches in diameter. Power 30 times, 7 50

1379. Achromatic Spy -glass, with wood body, and four draws, 37 inches

long when drawn out, 11 inches long when shut up ; object-glass

1& inches in diameter ; a very superior glass. Power 35 times, . 13 50

B. & J. BECK, PHILADELPHIA.

107

! I

108 R. & J. BECK, PHILADELPHIA.

No. Price.

1380. Achromatic Spy-glass, with wood body, and four draws, 42 inches

long when drawn out, 11£ inches long when shut up ; object-glass

2J inches in diameter, with sun-glass. Power 40 times, . . $20 00

1381. Achromatic Spy-glass, with wood body, and four draws, 48 inches

long when drawn out, 13£ inches long when shut up ; object-glass
2g inches in diameter, with sun-glass. Power 50 times, . . 30 00

1385. Achromatic Spy-glass, with metal body covered with Morocco,
two draws, 30 inches long when drawn out, 20 inches long when
closed; object-glass 1£ inches in diameter. Power 30 times, . 10 00

1387. Rifle Spy-glasses, 10 J inches long ; object-glass i inch diameter, . 2 50

1388. Naval Achromatic Spy-glass, tapering wood body and one draw,

55 inches long when drawn out, 45 inches long when shut up ;

rack and pinion for adjusting the focus. Power 50 times. . . 40 00

1389. Binocular Telescope on Stand, 115 oo

This instrument may be placed either on a broad window-sill or on a table,
and is intended for use at the sea-side or where there is an extensive prospect.
The Achromatic Object- Glasses are 1T% inches in diameter, magnifying 15 linear.
The adjustment for focus is made with rack and pinion. The distance between
the eyes is regulated by a small milled head on the top of the box. The two
wheels attached to one end of the Stand allow of a steady and easy horizontal
movement, and the large milled head underneath, (as shown in the illustration),
gives a vertical one.

1389.* Binocular Telescope for hand use, mounted as an ordinary
Field Glass. Object glasses 1T67 inch in diameter, magnifying
power 16 linear ; Sun and spray shade, in solid leather sling case,
complete, 60 00

1390. Wooden Tripod Stand, with vertical and horizontal motion, upon

which to place a spy-glass ; an exceedingly useful article, as a
glass of much power cannot be held in the hand with sufficient
steadiness to produce the best effect, : . 5 00

PORTABLE CLAMPS FOR SPY-GLASSES.

1391. Brass Clamp with Gimlet Screw, to fasten spy-glasses 1375 and

1376 to a Post or Tree, 1 75

1392. The same to fit spy-glass 1377, 2 00

1393. " " " 1378, 2 75

1394. " " " 1379, 3 25

1395. " " " 1380, 3 75

1396. " " " 1381, 4 25

EYE-PIECES FOR TELESCOPES.

1397. Celestial Eye-piece, of any power, made to order, .... 6 50

1398. Terrestrial Eye-piece, of any power, made to order, . . . 12 00

1399. Sun-glass fitted to any Telescope, 2 00

R. & J. BECK, PHILADELPHIA. 109

ASTRONOMICAL TELESCOPES.

There are few instruments which yield more pleasure and instruction than
the Telescope. Even a small instrument of only an inch and a half or two
inches aperture will serve excellently well to supply profitable amusement to
those who know how to apply its powers. Indeed, a well constructed Achromatic
of two to three inches aperture will not merely afford amusement and in-
struction— it may be made to do useful work. It is of this class of Telescopes
that we now propose to briefly speak, as we sell only those with Achromatic
object glasses.

The false coloring of the image produced by a single lens is due to Chromatic
Aberration. The pencil of light proceeding from a point, converges not to one
point, but to a short line of varying color, Thus a series of colored images is
formed, at different distances from the object-glass. So that if a screen were
placed to receive the mean image in focus, a colored fringe due to the other
images {out of focus, and therefore too large) would surround the mean image.
Happily it becomes possible to correct the chromatic aberration of one glass by
superadding that of another, and thus we have the Achromatic Objective. This
is effected by combining a convex lens of Crown glass with a concave lens of
flint glass, the convex lens being placed nearest to the object. A little color still
remains, but not enough to interfere seriously with the distinctness of the image.

But even if the image formed by the object-glass were perfect, if viewed
through a single convex lens of short focus, it would appear curved, indistinct,
colored and also distorted, because viewed by pencils of light which "do not pass
through the centre of the eye-glass. These effects are removed by using an eye-
piece, consisting of two lenses instead of a single one. Two forms are employed.
The first is Huyghen's, also called a negative eye-piece, because a real image is
formed behind the field-glass (the lens which lies nearest to the object-glass).
The second form is Ramsden's, also called the positive eye-piece, because the
real image formed by the object-glass lies in front of the field-glass. The
lenses are usually plano-convex, the convexities being turned towards the
object-glass in the negative eye-piece, and towards each other in the positive.
The negative form is used in all observations requiring distinct vision only,
whilst the positive is used for micrometrical measurements.

For the instruments described in the following list the ordinary mountings
on pillar and claw stand, or wooden tripod are sufficiently steady and convenient.
The larger and more elaborate Telescopes requiring Equatorial mountings will
be found described and illustrated further on among those of our own manufac-
ture. Those from Nos. 1400 to 1421 are made by Bardou of Paris, especially for
us, and bear our name and guarantee in addition to those of the famous maker.

An equatorially mounted telescope can be directed by means of the circles to
any celestial object whose right ascension and declination are known. On the
other hand, to bring an object into the field of view of an alt-azimuth, it is neces-
sary, either that the object itself should be visible to the naked eye, or else that
its position should be pretty accurately learned from the star maps, so that it
may be picked up by the alt-azimuth after a little searching. A small telescope,
called a finder, should be attached to all telescopes from the three-inch up,
intended for general observation. The finder has a large field of view, and is
adjusted so as to have its axis parallel to that of the large telescope. Thus a star
brought to the centre of the large field of the finder (indicated by the
intersection of cross lines placed at the focus of the eye-glass), is at, or very
near, the centre of the smaller field of the large telescope.

The Object-glass should be kept as free as possible from dirt, damp, or dust,

110 R. & J. BECK, PHILADELPHIA.

but it is not advisable to remove every speck which, despite such precaution,
may accidentally fall upon it. When it becomes necessary to clean the glass,
the substance used should be soft, perfectly dry, and free from dust. An old
silk or fine linen handkerchief, frequently washed and smoothly ironed, without
any starch, makes the best of all articles for this purpose. As the dust which has
fallen upon the object-glass is most probably gritty and therefore liable to scratch
the same, the proper method is to clean a small space near the edge of the glass,
and to sweep from that space as a centre. In this way the dust is pushed before
the silk, and does not cut the glass. It is always well to suspect the presence
of gritty dust, and adopt this cautious method of cleaning.
The two glasses should on no account be separated.

The Eye-pieces require to be as carefully preserved from damp and dust as
the Object-glass, and to be more frequently cleaned.

The telescope should not be mounted within doors if it can be conveniently
used on solid ground, as every movement in the house will cause the instru-
ment to vibrate unpleasantly. Further, if it is placed in a warm room, currents
of cold air from without will render objects under observation hazy and indis-
tinct. If the telescope is used in a room, the temperature of the latter should be
made as nearly equal as possible to that of the outer air.

The object, or the part of an object, to be observed, should be brought as
nearly as possible to the centre of the field of view. This of course is readily
done with an Equatorial mount moved by clock-work. But in the class of
instruments we are now considering, the best plan is so to direct the telescope,
by means of the finder, that the object shall be just out of the field of view, and
be brought (by the earth's motion) across the centre of the field. Thus the
vibrations which always follow the adjustment of the tube will have subsided
before the object appears. The object should then be intently watched during
the whole interval of its passage across the field of view.

It is important that the observer should recognize the fact that the highest
powers do not necessarily give the best views of celestial objects. High powers
in all cases increase the difficulty of observation, since they diminish the field
of view and the illumination of the object, increase the unsteadiness with
which (owing to the earth's motion) the image moves across the field, and mag-
nify all defects due to instability of the stand, imperfection of the Object-glass, or
undulations of the atmosphere. A good Object-glass of three inches aperture
will in very favorable weather bear a power of about 300, when applied to the
observation of close double or multiple stars, but for all other observations
much lower power should be used. Nothing but failure and annoyance can
follow the attempt to employ the highest powers on unsuitable objects or in un-
favorable weather.

In favorable weather the following is a good general test of the performance
of a telescope of two to three inches aperture, such as are named in this list : a
star of the third or fourth magnitude at a considerable elevation above the
horizon should exhibit a small well defined disc, surrounded by two or three
line rings of light.

The presence of fog or haze should not deter the telescopist from attempting
observations, since with a hazy sky, definition is often singularly good.
Neither must the observer expect distinct vision of objects near the horizon.
Objects near the eastern horizon during the time of morning twilight are espe-
cially confused by atmospheric undulations ; in fact, early morning is a very
unfavorable time for the observation of all the celestial bodies.

For a fuller account of the work which may be done with telescopes of two to
three inches aperture we refer the reader to the valuable little book, No. 1025
of this catalogue : " Half Hours with the Telescope," by Prof. Richard A. Proc-
tor, from which we have liberally quoted in compiling these remarks.

R. & J. BECK, PHILADELPHIA.

Ill

ASTRONOMICAL AND TERRESTRIAL TELESCOPES,

By Bardotj, Paris.

ACHROMATIC REFRACTORS.

No. 1399* to 1404 without Finder.

No. 1399* to 1404 with Finder.

No.
1399*.

1400.

Achromatic Telescope, ....

Body and Movements of highly rinished brass, with Rack and
Pinion adjustment of focus, Object-glass 2 inches in diameter,
One Terrestrial and One Celestial Eye-piece with Sun-glass,
powers 35 and 70 ; packed in a strong Walnut wood case, with
lock and key. The Telescope is mounted upon a firm Tripod
Stand of Mahogany, with prompt altitude and azimuth move-
ments, and arrangement for setting at any desired height for
convenient observation.

Achromatic Telescope,

Body and Mounting precisely the same as the foregoing. Object-
glass 2i inches in diameter, One Terrestrial and One Celestial
Eye-piece, with Sun Glass ; powers 35 and 80 ; in Walnut case.

Price.

$ 50 00'

60 00

112

R. & J. BECK, PHILADELPHIA.

No.
1401.

1402.

1403.

1404.

A.

B.

Achromatic Telescope,

Body, Mounting and Casing the same as the preceding. Object-
glass 2£ inches in diameter, Two Eye-pieces with powers of 40
and 90 and Sun Glass.

Achromatic Telescope, . . ....

The same in all respects as the above, but with Object-glass 3
inches in diameter, Two Eye-pieces of 50 and 110 times, with
Sun Glass ; in Walnut case.

Achromatic Telescope,

Body and Mounting all Brass, the same as all the above, mounted
on light but firm Mahogany Tripod, Object-glass 3£ inches in
diameter, One Terrestrial and One Celestial Eye-piece, with Sun
Glass ; powers 60 and 135 ; in Walnut case.

Price.

§70 00

100 00

175 00

No. 1405-1408.

Achromatic Telescope,

The same in all respects as the preceding, but with Object-glass
4 inches in diameter, Two Eye-pieces with powers of 70 and 145,
and Sun Glass; in Walnut case.

Achromatic Finder,

Fine Brass Mounting, with cross wires, adapted to Telescopes
1399*- to 1403.

Achromatic Finder,

Fine Brass Mounting, with cross wires, adapted to Telescope
No. 1404.

275 00

18 00

25 00

R. & J. BECK, PHILADELPHIA.

113

No.
1405.

Achromatic Telescope,

Body of finely finished, brass, mounted on a solid pillar of the
same material with claw feet, focal and altitude adjustments by
Rack and Pinion, the connecting rod of the latter entirely pre-
venting all usual vibrations, making the instrument very
steady ; azimuth adjustment by turning on a smoothly finished
plate, Object-glass three inches in diameter: two Terrestrial
Eye-pieces, powers 50 and 68, and Two Celestial ditto, powers 75
and 150, with Sun-glasses. The whole packed in a strong Walnut
wood case, with lock. A firm Mahogany Tripod, for out-uoor
use, accompanies this Telescope as shown in the illustration.

Price.

$150 00

No. 1409—11. >

1406. Achromatic Telescope,

Body and Mounting and all movements precisely the same as
in 1405. Object-glass 3£ inches in diameter, Two Terrestrial
Eye-pieces, powers 60 and 80, and Two Celestial ditto, p< >wers
100 and 175, with Sun-glasses; in Walnut wood case, with lock,
and with firm Mahogany Tripod.

250 00

114 R. & j. BECK, PHILADELPHIA.

^o. Price.

1407. Achromatic Telescope, ....... §350 00

Body, Mounting and all movements the same as in 1405 ; Object-
glass 4 inches in diameter, Two Terrestrial Eye-pieces, powers

70 and 90, and Three Celestial ditto, powers 110, 145 and 185, with
Sun-glasses ; in Walnut wood case, with lock, and Mahogany
Tripod.

1408. Achromatic Telescope, 425 00

Body, Mounting and" all movements the same as in 1405; Object-
glass 4£ inches in diameter, Two Terrestrial Eye-pieces, powers
75 and 95, and Three Celestial ditto, powers 115, 150 and 190, with
Sun-glasses; in Walnut wood case, witn lock and firm Mahogany
Tripod for out-door use.

A. Achromatic Finder, . . $ 18 00

Fine Brass mounting, with Cross Wires, adapted to Telescopes

1405 and 1406.

B. Achromatic Finder, 25 00

Fine Brass mounting, with Cross Wires, adapted to Telescopes
1407 and 1408.

1409. Achromatic Telescope, . . . . . . 175 00

Body of finely finished brass with Rack and Pinion adjustment
of focus, and very steady and smooth altitude and azimuth
movements. The Telescope is mounted upon a very firm and
steady Tripod of Mahogany and can be raised to any desired
height by a Rack and Pinion worked by a crank so that obser-
vations may be made either sitting or standing, as desired. The
construction of the Tripod stand, allows the folding of the legs,
rendering the whole instrument very portable, for carrying, with-
out dismounting the tube. The Object-glass is three inches in
diameter, and there are four Eye-pieces, two Terrestial, with
powers of 50 and 68, and two Celestial, with powers of 75 and 150,
with Sun-glasses. In Walnut case with lock.

1410. Achromatic Telescope, 250 00

Body, stand, and all appliances the same as in 1409. Object-glass
.S^inehes in diameter, two Terrestial Eye-pieces giving powers of
>60 and 80, and two Celestial ditto, with powers of 100 and 175,
with Sun-glasses. In Walnut wood case with lock.

141L Achromatic Telescope, 350 00

Body, stand, and all appliances the same as^the preceding. Ob-
ject-glass 4 inches in diameter, two Terrestial Eye-pieces, powers
70 and 90, and three Celestial ditto, powers 110, 145, and 255, with
Sun-glasses. In Walnut wood case with lock.
1406*:. Achromatic Telescope, . .... 250 00

Fine Brass body, with solid joint for inclination, Rack and Pinion
adjustment of focus, and vertical and horizontal movements by
tangent screws. Heavy, solid Mahogany Tripod, with mechan-
ical arrangement for raising the Telescope to any desired height.

• Object-glass 3 inches in diameter, two Terrestial Eye-pieces,
powers 50 and 68, and two Celestial ditto, powers, 75 and 150,

• with Sun-glasses. In Walnut wood case with lock.

1410.* Achromatic Telescope , 350 00

Body, stand, and all appliances the same as in 1409*. Object-glass

R. & J. BECK, PHILADELPHIA.

115

No. Price.

3} inches in diameter, two Terrestial Eye-pieces with powers of
60 and 80, and two Celestial ditto, with powers of 100 and 175, with
San-glasses. In Walnut wood case with lock.

1411*. Achromatic Telescope, $550 oo

Body, stand and all appliances the same as the preceding. Ob-
ject glass 4 inches in diameter, two Terrestial Eye-pieces, powers
70 and 90, and three Celestial ditto, powers 110, 145 and 255, with
Sun-glasses. In Walnut wood case with lock.

A. Achromatic Finder, 18 oo

Fine Brass mounting, with Cross Wires, adapted to Telescopes
1409-10 and 1409*-10*.

B. Achromatic Finder, . 25 oo

Fine Brass mounting, with Cross Wires, adapted to Telescopes
1411 and 1411*.

1412.

1414-15.

1412-13.

1416-17.

Achromatic Telescope,

In this instrument and those immediately following, whilst the
optical portions are First Class, the mountings have been specially
designed and constructed to combine excellence of workmanship
with great moderation in price. 1412 has metallic body with
Rack and Pinion adjustment of focus, with vertical and horizon-

60 00

116 R. & J. BECK, PHILADELPHIA.

No. Price.

tal movements, mounted upon a cast-iron Tripod, neatly ja-
panned. The Object-glass is 3 inches in diameter, and there are
three Eye-pieces, one Terrestial,power 50 times, and two Celestial,
powers 110 and 150, with !Sun-giasses. Packed in strong Deal case.

1413. Achromatic Telescope, $225 00

Body, Mounting and all appliances precisely the same as with
1412; Object-glass 4i inches in diameter, One Terrestrial Eye-
piece, power 60, Two Celestial ditto, powers 140 and 300, with
Sun-glasses ; in Deal case.

1414. Achromatic Telescope, 65 oo

Body and Movements the same as the preceding, but mounted
upon a strong, firm Tripod of hard wood for out-door use ; Ob-
ject-glass 3 inches in diameter, One Terrestrial Eye-piece, power
50 times, and Two Celestial ditto, powers 110 and 150, with Sun-
glasses ; in strong Deal case.

1415. Achromatic Telescope, , 230 oo

Body, Mounting and all appliances the same as with 1414; Ob-
ject-glass 4i inches in diameter, One Terrestrial Eye-piece,
power 60 times, and Two Celestial ditto, powers 140 and 300, with
Sun-glasses ; in Deal case.

1416. Achromatic Telescope, . . . . , . . 75 oo

Body with Rack and Pinion adjustment of focus, and prompt
movements in Altitude and Azimuth, is mounted on a firm
Tripod of hard wood for out-door use, having in addition a
small Tripod Stand of Japanned cast-iron for use upon a table ;
Object-glass 3 inches in diameter, One Terrestrial Eye-piece,
power 50 times, and Two Celestial ditto, powers 110 and 150, with
Sun-glasses ; in strong Deal case.

1417. Achromatic Telescope, 250 oo

Body, Mounting and all appliances the same as with 1416 ; Ob-
ject-glass 4j inches in diameter, One Terrestrial Eye-piece, power
60 times, and Two Celestial ditto, powers 140 and 300, with Sun-
glasses ; in Deal case.

A. Achromatic Finder, 18 oo

Fine Brass Mounting, with Cross Wires, adapted to Telescopes
1412-14-16.

B. Achromatic Finder, . ....... 25 oo

Fine Brass Mounting, with Cross Wires, adapted to Telescopes
1413-15-17.

REFLECTING TELESCOPES.

1418. Alt-Azimuth Reflecting Telescope, 225 00

With Finder, Glass Parabolic Silvered Mirror 4 inches in diam-
eter, mounted on firm Tripod of Cast-iron, Three Eye-pieces,
giving powers from 50 to 200 times.

1419. Alt-Azimuth Reflecting Telescope, 525 oo

With Finder, Glass Parabolic Silvered Mirror 6J inches in
diameter, mounted on Solid Iron Tripod, Three Eye-pieces,
with powers from 60 to 300 times.

R. & J. BECK, PHILADELPHIA,

117

Nos. 1418-19.

No.
1420

Equatorial Reflecting Telescope, ....

With Finder, Glass Parabolic Silvered Mirror 61 inches in
diameter, declination circle 8 inches in diameter, hour circle
14J inches ditto, Four Eye-pieces, giving powers from 60 to 300
times.

1421. Equatorial Reflecting Telescope,

With Finder, Glass Parobolic Silvered Mirror 8 inches in diam-
eter, declination circle 13 inches in diameter, hour circle 18J-
inches ditto, Four Eye-pieces, powers from 65 to 400 times.

Driving Clock for the above,

These Telescopes are only Imported To Order.

Price.

$925 00

1800 00

300 00

118

R. & J. BECK, PHILADELPHIA.

No. 1420-21.

No.

BARDOU'S ACHROMATIC OBJECT-GLASSES,

Mounted in Brass Cells.

«

1475.

Achromatic Object-glass,

3

inches, 75

1476.

n (<

3i

" 81

1477.

it a

32^

88

1478.

it ((

31

" 95

1479.

(( it

4

" 102

1480.

it a

4i

109

1481.

(< «

4i

" 115

1482.

U ((

5

" 128

1483.

«( ((

6

" 149

Price.

. . . § 25 00

35 00

50 00

75 00

100 00

125 00

150 00

200 00

350 00

R. & J. BECK, PHILADELPHIA. Jig

ASTRONOMICAL TELESCOPES.

Our Own Manufacture.
No. Price;

1422. Astronomical. Telescope on Pillar - and - Claw Stand.

Achromatic Object-glass 2i inches in diameter. Focal length
3 feet. One Terrestrial Pancratic Eye-piece, magnifying from
15 to 30 linear; one Astronomical Eye-piece with Sun-shade,
magnifying 60 linear. Focal ittljustment by Rack and Pinion.
Mounted on handsome Pillar-and-Claw Stand. The whole packed
in a strong Mahogany case. $115 00

1423. Astronomical Telescope on Pillar-and-Claw Stand. Ach-

romatic Object-glass 25 inches in diameter. Focal length 3V feet.
Pancratic Terrestial Eye-piece, magnifying from 20 to 40 linear.
Three Astronomical Eye-pieces, with Sun-shades, magnifying
respectively about 20, 60 and 100 linear: Rack-and-Pinion
Adjustment to the focus. Telescope mounted on handsome
Pillar-and-Claw Stand as No. 1422. The whole packed in a
strong Mahogany case, . . , . , . . . 175 00

1424. Astronomical Telescope on Pillar- and-Tripod Stand. Ach-

romatic Object-glass 2| inches in diameter, Focal length 3^ fe^t.
Pancratic Terrestrial Eye-piece, magnifying from 20 to 40
linear. Three Astronomical Eye-pieces, with Sun-shade,
magnifying respectively about 20, 60 and 100 linear. First-
surface Diagonal Reflector for observing the Sun, Rack-and-
Pinion Adjustment to the focus. Finder same as No. 1425,
and Dew-shade. Telescope mounted on Pillar-and-Tripod Stand,
with Vertical and Horizontal movements by Rack and Screw,*
and Steadying-rods. The whole packed in a strong Mahogany
case, 225 P0

1425. Astronomical Telescope on Pillar-and-Tripod Stand.

Achromatic Object-glass 3^ inches in diameter, Focal length 4
feet. Pancratic Terrestrial Eye-piece, magnifying from 20 to 40
linear. Four Astronomical Eye-pieces, with Sun-shades, magni-
fying respectively about 20, 40, 60 and 100 linear. First-surface
Diagonal Reflector for observing the Sun, Rack-and-Pinion
Adjustment to the focus. Finder and Dew-shade. Telescope
mounted on Piilar-and-Tripod Stand, with Vertical movement
by Rack and Pinion, and Horizontal movement by an endless
Screw. Sliding Steadying-rods. The whole packed in a strong
Mahogany case, . . 350 00

1426. Astronomical Telescope on an Equatorial Stand. Achro-

matic Object-glass 3& inches in diameter, Focal length 4 feet.
Pancratic Terrestrial Eye-piece, magnifying from 20 to 40 linear.
Four Astronomical Eye-pieces, with Sun-shades, magnifying
respectively about 20, 40, 60 and 100. First-surface Diagonal
Reflector for observing the Sun. Finder as in No. 1427, Rack-
and-Pinion Adjustment to the focus. Telescope mounted on a
strong Equatorial Stand. Declination Circle 4 inches in diameter,
divided to 30', with two Verniers reading to 30". The Hour
Circle 4 inches in diameter, divided to 2 minutes, with two
Verniers reading to 2 seconds of time. The Polar Axis and De-
clination Axis of brass, fixed on a strong cast-iron Column, with
adjustments for Latitude, Azimuth, etc. The Telescope and
Equatorial part packed in Mahogany cases, • • • • 475 iKi

120

R. & J. BECK, PHILADELPHIA.

No. 1427.

E. & J. BECK, PHILADELPHIA. 1 21

No. prick.

1127, Astronomical Telescope on an Equatorial Stand. Achro-
matic Object-glass 4£ inches in diameter, Focal length 5i feet.
Four Astronomical Eye-pieces, with Sun-shades, magnifying re-
spectively about 20, 40, 70 and 140. First-surface Diagonal
Reflector for observing the Sun. Finder. Rack-and-Pinion
Adjustment to the focus. Complete Illuminating apparatus.
Telescope mounted on a strong Equatorial Stand. The Declina-
tion Axis fitted into a cast-iron Socket, bolted on to the Polar
Axis. The Declination Circle 8 inches in diameter, divided to
3CK, and reading to 30" of arcv The Polar Axis, working in a
fitting and on a Steel Ball, and attached to it a Right- Ascension
Circle, 8 inches in diameter, divided to minutes, with two
Verniers, reading to seconds of time. This Circle is arranged so
that the Telescope can be set in Right Ascension without any
calculation. A Driving Circle connected with the Clock, whose
rate is governed by Balls and Fans: this can be detached at
pleasure. A fine adjustment in Declination fixed to the Tele-
scope, and all other necessary adjustments supplied. The whole
mounted on a strong cast-iron Column, with ready adjustments
for Latitude, Azimuth, etc., $1000 M

3428, Astronomical Telescope on an Equatorial Stand. Achro-
matic Object-glass 5 inches in diameter, Focal length about 6 feet,
6 inches. Five Astronomical Eye-pieces, with Sun-shades, mag-
nifying respectively about 40, 60, 100, 150 and 200. First-surface
Diagonal Reflector for observing the Sun. Position Circle at
Eye-end graduated on Silver, with two Verniers and Micro-
scopes, reading to minutes. Finder and Dew-shade, Rack-and-
Pinion Adjustment to focus. Parallel Wire Micrometer with
Double Movable Lines, four Eye-pieces, magnifying about 200,
300, 400 and 600 linear. Complete Illuminating apparatus. Tele-
scope mounted on a strong Equatorial Stand. The Declination
Axis fitted into and working in a cast-iron Socket, bolted on the
Polar Axis. The Declination Circle 12 inches in diameter, divi-
ded to 10', with two Verniers and Microscopes, reading to 10" of
arc. To the Polar Axis is fixed a Right- Ascension Circle, divided
to 2 minutes, with two Verniers, reading to 2 seconds of time.
This Circle is arranged so that the Telescope can be set in Right
Ascension without any calculations. A Driving Circle is con-
nected with the Clock, whose rate is governed by Balls and
Fans : this can be thrown out of gear at pleasure. Fine adjust-
ments in Right Ascension and Declination by means of Tangent
Screws and Hooks' joints, conveniently placed. The whole
mounted on a strong cast-iron Pillar, with ready adjustments
for Latitude, Azimuth, etc., 1500 00

1429. Astronomical Telescope on Equatorial Stand. Achromatic
Object-glass 6" inches in diameter, Focal length about 7 feet, 6
inches. Six Astronomical Eye-pieces, with Sun-shades, magni-
fying respectively about 40, 60, 100, 150, 200 and 400 linear. First-
surface Diagonal Reflector for observing the Sun. Position Cir-
cle at Eye-end graduated on Silver, with two Verniers and
Microscopes, reading to minutes. Finder and Dew-shade, Rack-
and-Pinion Adjustment to focus. Parallel Wire Micrometer,
with Double Movable Lines, four Eye-pieces, magnifying
about 200, 300, 400 and 600 linear. Complete Illuminating appa-
ratus. Telescope mounted on a strong Equatorial Stand. The
Declination Axis bolted at right angles to the Telescope, and

122

No.

R. & J. BECK, PHILADELPHIA.

PUICE

1431.

1432.
1433.
1434.

1437.
1439.
1441.
1443.
1444.
1446.

fitted into an iron socket bolted on the Polar Axis. The Declina-
tion Circle, 16 inches in diameter, divided to 10', with Two Ver-
niers and Microscopes, reading to 10" of arc. To the Polar Axis
is fixed a Right-Ascension Circle, divided to 2 minutes, with two
sets of Verniers, reading to 2 seconds of time. This Circle is ar-
ranged so that the Telescope can be set in Right Ascension
without any calculations. A Driving Circle connected with the
Clock, whose rate is governed by Balls and Fans : this can be
thrown in and out of gear at pleasure. Fine adjustments in
Right Ascension and Declination by means of Tangent Screws
and Hooks' joints, conveniently placed. The whole mounted on
a strong cast-iron Pillar, with ready adjustments for Latitude,
Azimuth, etc., ........... §2400 00

Parallel "Wire Micrometer, Double Movable Lines, four
Eye-pieces, powers varied at pleasure packed in a Mahogany

case, 100 Ofl

Double Image -Micrometer, 100 00

AnitdTiAB Micrometer, with Eye-piece, 8 00

Micrometer, ruled on Glass to parts of an Inch or Metre, fitting

any Eye-piece, 4 00

Illuminating Apparatus, 40 on

Driving-Clock and Connecting Gear, 80 00

Diagonal Reflector, First-surface glass for Solar observations, 15 CO

Heygenian Eye-piece, any power, 7 50

Sun-Shade, . 2 00

Varley's Telescope-Stand, complete fittings, .... 100 00

Special Estimates given for Mounting Telescopes.

OBJECT-GLASSES, First Quality, Mounted in Brass Cells.

1451. Object-Glass, ly1^ inches diameter, Focal Length, 9 inches, . . 4 00

1 foot, 6 inches, 6 00

2 feet, . . 10 00

3 feet, . . 20 00

3 feet, 6 inches, 50 00

4 feet, . . 100 00

5 feet, 6 inches, 240 00

6 feet, G inches, 320 00

7 feet, 6 inches, 550 00

1452.

a i

' ItV

a a

1453.

a i

' lA

a u

1454.

a i

' 21

II ((

1455.

« (

' 25

({ II

1456.

II i

3}

(< (<

1457.

II <

1 4'.-

(< (<

1458.

(( <

' 5

ti a

1459.

« «

6

II II

Telescopes 1400 to 1408 are of most excellent construction, with well-corrected
Object-glasses, and very finely mounted. Those from 1422 to 1429 are of the very
finest quality ; no pains being spared to render them first-class in every respect.

E. & J. BECK, PHILADELPHIA.

123

124

R. & J. BECK, PHILADELPHIA.

ACHROMATIC MARINE AND FIELD GLASSES.

These Glasses are designated according to the diameter of the Object-glasses
in French lines, as follows :

11 Lines are equal to 1 inch.

13 "

15 "

17 "

19 "

21 "

24 "

26 " "

They are all constructed with six lenses, unless the contrary is specially
stated^ and are invariably well corrected and adapted to all visions.

ll36

inches.

1*

u

n

<(

m-

«

i*

«

2*

if

2&

(«

1500-1502.

No.

Prick
$5 00

1500. Binocular Horizon Sweep, in solid Leather sling case,

This glass has been expressly designed and constructed at our own works, for
yachting purposes, and to meet the requirements of Captains. The framework,
which is of brass, bronzed, and covered with strongly-stitched leather, is made
very strong. The Achromatic Object-glasses are carefully corrected, and the
Eye-pieces are arranged so as to give the maximum amount of light, thus ren-
dering it especially useful in foggy weather or during twilight. The solid
Leather case is of the very best make.

E. & J. BECK, PHILADELPHIA.

No.

1501. Lemaire's U. S. Army Signal Service Marine or Field Glass,

metal body, covered with Turkey Morocco, Sun-shades to
extend over the Object-glasses, and heavy Leather case, with
strap ; very superior.

Object-glasses, 19 lines in diameter,

4 4 Q-l it 4 4

£*■ .....

24 "

" 26 " "

1502. Bardou's U. S. Army Signal Service Marine or Field Glass, body

covered with Turkey Morocco, Sjin-shades to extend over the
Object-glasses, in fine Leather case, with strap ; the best article
made. This glass bears our own trade-mark, and is made
expressly for our sales.

Object-glasses, 19 lines in diameter,

" 21 " " .

" 24 " "

" 26 " " .

1503. Bardou's U. S. Army Signal Service Marine or Field Glass, the

same as 1502, with addition of a hinge adjustment for varying
distance between the eyes, in stiff Leather case, with strap.
Object-glasses, 19 lines in diameter, . . .

" oi a 44'

-j1 . » • • •

" 24 " "

u 26 " " .

1504.
1504. Field Glass, metal body, covered with Morocco, Sun-shades to
extend over the Object-glasses, and stiff Leather case, with strap;
an excellent glass.

Object-glasses, 19 lines in diameter, .....

44 91 44 44

11 24 "

» 26 " "

Binocular Glass, with three adjustable Eye-pieces of different
powers, Field, Marine or Opera, metal bodies, covered with
finest Turkey Morocco, Sun-shades to extend over the Object-
glasses, and fine Leather case, with strap.

Object-glasses, 17 lines in diameter,

« 19 " "

« 21 " 4i .

" 24 " "

1506.

125

Price.

$13 50
15 00

17 00

18 00

20 0C

21 00

22 50
25 00

22 50
24 00

26 00

27 50

8 00

10 00

11 00

12 00

16 00
18 03
20 00

22 M

126

No.

R. & J. BECK, PHILADELPHIA.

Price

No. 1506.

No. 1507.

1507. Field Glass, Rock Crystal Lenses, double adjustment of focus, so
that, when closed, the instrument can be conveniently carried in
the pocket, in Morocco case, without strap ; very powerful, but
small field of view.

Object-glasses, 10 lines in diameter,

a ii a a

J--L • • . . «

Li K it (<

■L'J • • • • >

(( 17 << u

J-i • • • • >

THE GEM.

14 00
16 00
18 00
20 00

rt.Sf*^0'-

No. 1510.

1510. The Gem, Field and Opera Glass, Object-glasses 19 lines in diam-
eter, ....'. $20 00

This is the most powerful Glass of its size ever made, combining all the power
and scope of a Field or Race Glass, with the portability and neatness of an
Opera Glass. It is made in the most thorough manner at our own works, and is
furnished either in a stiff Leather case, with sling for field use, or in a soft
Leather case for the Opera.

loll. The Gem, Field and Opera Glass, the same in quality and power
as 1510, but made with telescope tubes, so that packed in case it
occupies a space of only 5 x 2£ inches. In Soft Leather Case, . $25 00

1512. The Pearl, Field and Opera Glass, similar to the Gem in style

and case, Object-glasses, 21 lines, 15 00

K. & J. BECK, PHILADELPHIA.

127

OPERA GLASSES.

No.

1515. Opera Glass, frame work all black, metal bodies covered with

Dlack leather, in soft Leather case.

Object-glasses, 13 lines in diameter,

15 '•' "

(< 17 " "

19 " "

1516. Opera Glass, black metal frames, very substantial, bodies cov-

ered with black Morocco, in soft Leather case.
Object-glasses, 11 lines in diameter,

11 13 " " . .

(C 1 - li u

1m) . *

17 » " . .

" 19 " " .

PRICj

$3 50

4 00

4 50

5 00

5 00

5 50

6 00

7 00

8 00

Nos. 1515-1517.

1517. Opera Glass, black metal frames, bodies covered with colored
Morocco in handsome dark shades, in soft Leather case.

Object-glasses, 11 lines in diameter, . . " . . . 3 50

13 " " 4.00

15 " " ..... 4 50

" 17 . " " ..... 5 00

" 19 " " .... 6 00

No. 1518.

No. 1519

1518. Opera Glass, very substantial, black metal frames, bodies cov-
ered with black Morocco, patented Eye-pieces, readily adjustable
to the vision of the nearest-sighted person as well as to that of
the far-sighted, in soft Leather case.

Object-glasses, 15 lines in diameter, ......

XI » • . . •

it in t« "

j.y • « • • •

12 00

13 50
15 00

128

No.
1519.

R. & J. BECK, PHILADELPHIA.

Opera Glass, tops and cross-pieces black, tubes and bottom
pieces richly gilt, bodies covered with handsome colored Mo-
rocco, with gilt trimmings top and bottom, very handsome and
excellent glasses ; in soft Leather case.

Object-glasses, 11 lines in diameter,

ii 13 t<

" 15 «

" 17 «

" 19 "

1520. Opera Glass, for the vest pocket, very small but with a large
clear field of view, black metal frames, bodies covered with black
Morocco with silk sling and in case.

Object-glasses, 13 lines in diameter,

" 15 " "

Prich

$8 50
9 00
10 50
12 00
14 00

9 00
10 00

LEMAIRE'S AND BARLWS OPERA GLASSES.

Xos. 1525-1527.

Xos. 1530-1536.

1525. Opera Glass, (Lemaire's), substantial black metal frames, bodies

covered with best black Morocco leather, in soft Leather case.

Object-glasses, 11 lines in diameter,

13 "

15 "
" 17 u

(i 19 U U

1526. Opera Glass, (Lemaire's), substantial black metal frames, bodies

covered with handsome colored Morocco leather of various
shades, in soft Leather case.

Object-glasses, 11 lines in diameter,

" 13 " "

" 15 " •*

(« it u ((

J./ » . • . •

19 " "

1527. Opera Glass, (Lemaire's), tops and cross-pieces black metal,

tubes richly gilt, bodies covered with handsome colored Morocco
leather of various shades, in soft Leather case.

Object-glasses, 11 lines in diameter,

13 " " .
11 15 " "

(i 17 a if

" 19 " " .

$6 00

6 50

7 00

8 00

9 00

6 00

7 00

7 50

8 00

9 00

7 00

7 50

8 50

9 00
10 00

R. & J. BECK, PHILADELPHIA.

NO.

1530. Opera Glass, (Bardou's), light but very strong, black metal

frames, bodies covered with finest black Morocco leather, in
soft Leather case, very superior in power and size of field.
Object-glasses, 12 lines in diameter,
" 15 " "

(( yr ft If

" 19 " "

1531. Opera Glass, (Bardou's), the same in all respects as 1530, but

with triple Object-glasses and Eye-pieces, making twelve lenses
in all ; exceedingly powerful and perfect definition.
Object-glasses, 12 lines in (liameter,
" 15 " "

a yr If «

" 19 " "

1532. Opera Glass, (Bardou's Conical), very strong, black metal

frames, the tapering bodies covered with the finest Turkey
Morocco leather, in soft Leather case. These are very superior
and powerful Opera Glasses, and are equally well adapted to
Field or Marine use.

Object-glasses, 13 lines in diameter,
" 15 " "

ft yj ft a

" 19 " "

ti 21 " "

1535. Opera Glass, (Bardou's), tops and cross-pieces all black, tubes

and bottoms richly gilt, bodies covered with finest colored
leather, in soft Leather case ; very superior.

Object-glasses, 12 lines in diameter,

ft IK ft ft

±o • • • • •

U yr u ff

1536. Opera Glass, (Bardou's), the same in all respects as 1535, with

addition of richly gilt trimming at top and bottom of bodies*

Object-glasses, 12 lines in diameter,

tt IK tf it

±o • • . . •

tt -17 tt tt

j-l . . • • •

19 " "

129

Pfii-uiii.

$8 00

8 50

9 50
11 00

13 00

14 00
16 00

18 00

9 00

9 50

11 50

13 50

15 00

12 50

13 50

15 00

17 00

13 50

15 00

16 00

17 50

PEARL OPERA GLASSES.

1540. Opera Glass, (Lemaire's), tubes and cross-pieces richly gilt

metal, tops and bodies of the finest pure white Pearl, in fine soft
Leather case ; elegant glasses.

Object-glasses, 11 lines in diameter,

u 13 tt tt

il 15 tt tt

tt 27 " "

" 19 "

1541. Opera Glass, (Lemaire's), tubes and cross-pieces richly gilt

metal, tops and bodies of superb iridescent Oriental Pearl,
in fine Leather case ; magnificent glasses.

Object-glasses, 11 lines in diameter,

ft 19 ft ft

-LO « • ■ • •

" 15 " "

ft 27 l* "

" 19 " "

10 00

12 00

13 50
15 00
17 50

12 00

13 50
15 00
17 50
20 00

130 R. & J. BECK, PHILADELPHIA.

No.

1542. Opera G;lass, (Lemaire's), tubes and bottoms of metal, richly-
gilt, cross-pieces nickel-plated, tops and bodies of rich dark
colored Pearl ; very elegant, in soft Leather case.

Object-glasses, 13 lines in diameter,

" 15 " "

" 17 " "

■" 19 " "

Nos. 1540-1545.

1543. Opera Glass, (Lemaire's), tops, tubes and cross-pieces all black
metal, bodies of black Pearl ; very rich, in soft Leather case.

Object-glasses, 13 lines in diameter, . . .

a it; it ((

(i jg (< <(

1545. Opera Glass, (Bardou's), tubes and cross-pieces of richly gilt
metal, tops and bodies of the purest white Pearl; the most
elegant glass in the market, in soft Leather case.

Object-glasses, 12 lines in diameter,

iu • • . • .

a -"" << u

j-i • . . •

19 " " ....

ALUMINIUM OPERA GLASSES.

Price.

$15 CO
17 00
20 00
22 50

10 00
li 50
13 50
15 00

20 00
2i 00
22 50
25 00

The wonderful lightness of this metal admirably adapts it for use in the
frames and bodies of Opera and Field Glasses, no fatigue attending their con-
tinued use for hours.

1550. Opera Glass, Aluminium Frame, bodies covered with finest

black Calfskin or dark-colored Russia Leather, tops and cross-
pieces black, tubes and milled edges Bright Metal, in soft
Leather case.

Object-glasses, 15 lines in diameter, $18 50

" 17 " " 22 00

" 19 " " 25 00

" 21 " " 28 50

1551. Opera Glass, Aluminium Frame, bodies covered with finest

black Calfskin, tops, tubes and cross-pieces all Bright Metal,
very handsome ; in soft Leather case.

Object-glasses, 15 lines in diameter, 20 00

17 " " ..... 23 50

" 19 " " 27 00

" 21 " " 30 00

R. & J. BECK, PHILADELPHIA.

No.

1553. Opera Glass, Aluminium Frame, bodies covered with the finest
dark colored Russia Leather, tops, cross-pieces and tubes all of
Bright Metal, very rich and elegant ; in soft Leather case.

Object-glasses, 15 lines in diameter,

a yj ft (I

" 19 " "

a oi u it

^A • • • • •

131

Price.

$21 00
24 00
27 50
31 00

ALUMINIUM FIELD OR MARINE GLASSES.

1555. Marine or Field Glass, Aluminium Frame, bodies — 4J inches

long when closed, 5 inches long when fully extended — covered

with the finest black Calfskin, tops and cross-pieces black, tubes

Bright Metal, with Sun-shades ; in stiff Leather case, with sling

Object-glasses, 19 lines in diameter,

tt 21 " "

(< 04 " "

" 26 " "

1556. Marine or Field Glass, Aluminium Frame, the same size as

1555; bodies covered with finest black Calfskin, tops, tubes and
cross-pieces all Bright Metal, very handsome, with Sun-shades
in stiff Leather case, with sling.

Object-glasses, 19 lines in diameter, ....

" 21 " " ....

^ ^t ....

" 26 " " ....

1557. Marine or Field Glass, Aluminium Frame, bodies — 4£ inches

long when closed, 6 inches long when fully extended — covered
with the finest black Calfskin, tops and cross-pieces all black,
tubes of Bright Metal, with Sun-shades; in stiff Leather case,
with sling.

Object-glasses, 19 lines in diameter,

" 21 " "

<4 24 " "

« 26 " "

1558 Marine or Field Glass, Aluminium Frame, the same size as
1557 ; bodies covered with finest black Calfskin, with Sun-shades,
tops, tubes and cross-pieces all Bright Metal, very elegant ; in
stiff Leather case, with sling.

Object-glasses, 19 lines in diameter,
" 21 " "

a 24 " "

" 26 " "

1559. Marine or Field Glass, Aluminium Frame, with hinge to

adapt for various widths between eyes, the same size as 1555 ;

bodies covered with finest black Calfskin, with Sun-shades, tops,

tubes and cross-pieces all Bright Metal ; the most elegant glass

made ; in stiff Leather case, with sling.

Object-glasses, 17 lines in diameter,

19

" 21 " "

" 24 " "

» 26 " "

32 50
30 00
43 00
47 50

35 00
39 00
45 00
50 00

35 00
40 00
45 00
50 00

37 50
41 00
47 00
52 50

37 50
42 00
47 00
52 50
57 50

SPECTACLES AND EYE-GLASSES.

INTRODUCTION.

In no branch of Surgery has more advance been made of late years than in
that department which treats of imperfections in vision. The careful study of
the various portions of the Eye, and the introduction of the use of the Ophthalmo-
scope, have led to many important discoveries, and the Ophthalmic Surgeon, in
order to carry out his necessary prescriptions, has rightly demanded of the
Manufacturing Optician that he should pay some attention to the Scientific Con-
struction of Spectacles. Nothing tends more to injure the sight than wearing
improper glasses, especially concave ones, whilst nothing preserves vision more
than the use of suitable ones.

With a view to make this Part of our Catalogue practically useful, we have
given herewith short descriptions of the anatomy of the Eye, and of some of the
more frequent forms of defective vision which may be assisted by the use of
glasses ; and for the convenience of persons residing at a distance we have printed
a set of Test Types, and have given a series of queries, accurate answers to which
will enable us to supply glasses suited to most imperfections of vision, whilst
we have also enumerated some of those Complaints for any of which the patient
should at once consult the Oculist, whose directions we are always ready to
carry oui.

The Illustrations, which have been engraved with great care, will give an idea
of the various forms and patterns of the Frames of our Spectacles and Eye-
Glasses, whilst the quality of the Glasses with which they are glazed is uniformly
First Class only. We sell no others, at retail. Spectacles should be made to fit
firmly on the face without pinching ; much of the comfort attending their use
depends on their so doing ; and the more complete the information given as to
the shape of the head, the better are we enabled to suit the patient.

Fig. II.

Fig. III.

132

^* *i

K. & J. BECK, PHILADELPHIA.

133

MAGNIFIED VIEW OP A SECTION THROUGH THE MIDDLE OP THE EYE. A,

SCLEROTIC COAT ; B, CORNEA ; I, CRYSTALLINE LENS ; K, RETINA J

P, CHOROID COAT J D, ENTRANCE OF OPTIC NERVE.

134

R. & J. BECK, PHILADELPHIA.

THE BYE.

We undoubtedly derive more of our knowledge of the world about us through
the agency of sight, than through any other member of the group of our special
senses, but, although of such great importance to us all, there are comparatively
few persons who have definite ideas concerning the eye, either as to its struc-
ture or the manner in which it aids in the production of vision.

In the following pages will be found a concise description of the eye itself
and explanations of its mode of action in health, together with a brief outline
of the abnormal conditions, which we, as opticians, are called upon to treat.

ANATOMY OF THE EYE.

SECTION OF A DIAGRAMATIC EYE (AFTER HELMHOLTZ.)

The shape of the eyeball is nearly spherical, with a diameter of almost one
inch ; viewed from the side, however, we find it to be composed of parts of two
spheres, the smaller one being formed of the transparent cornea (F), which
projects forward, as may be readily seen in looking at any eye from the side.

R. & J. BECK, PHILADELPHIA. 135

The eye is provided with six muscles : two pulling it to the right or left, two
up or down, while the remaining two rotate the ball obliquely, at the same time
drawing it either up or down. Each eye is provided with its own set of muscles
but these act in unison, thus causing both eyes to be directed simultaneously to
any object which we view.

f. The Cornea. This is the transparent front, through which the "color" of
the eye is seen ; although it appears clear and structureless, yet under the
microscope it shows a complicated structure. The cornea is the first part of
the refractive system of the eye.

m. The Sclerotic coat is the thickest tunic or covering of the eyeball,
and forms the " white" of the eye. It is a tough, elastic membrane, and is well
calculated to give form to the organ and protection to the more delicate parts
within.

b. The Iris is a thin, muscular curtain which hangs in front of the lens (A), and
serves the purpose of a diaphragm, cutting off all superflous light. It is perfo-
rated in the centre, thus leaving a circular opening knoAvn as the u Pupil."
The iris is variously tinted, thus causing the diversity in the "color" of eyes ;
the pupil forms the "black" of the eye. As the iris contracts the pupil be-
comes smaller, and, on the contrary, as the former dilates, the latter en-
larges ; this change in size being regulated by the amount and intensity of the
light which passes into the eye — the greater the amount of light, the smaller
the pupil.

g. The CJioroid coat is the second tunic of the ball ; it is quite thin, and it is the
vascular coat of the eye, containing hundreds of minute tortuous blood-vessels.
On its inner surface it is covered with a dense layer of black pigment, which
absorbs all light which falls upon it, and thus prevents reflection. In many
animals, as the cat, tiger, etc., a certain portion of the choroid, called the tapetum,
is devoid of this pigment, and has a metallic lustre instead ; the reflection of
light from this spot gives rise to the well-known glare of the eyes of these
animals when approached with a light in the dark.

A. The Crystalline Z,ens is a perfectly transparent, highly refractive body,
shaped like a biconvex lens, with the curve of its posterior surface slightly greater
than that of the front; it is supported between the iris and the vitreous humor.
The lens is capable of having the convexity of its surfaces increased or dimin-
ished by the action of the ciliary muscle (H), which change is of the greatest
importance, since it enables us to "accommodate," that is, to see far and near
objects equally well.

h. The Ciliary muscle is a delicate band of muscular tissue, which forms a
complete circle, lying just behind the iris. Although small and insignificant in
appearance, it is a very essential part of the eye, as by its action, contracting now
more, then less, the convexity of the lens is increased or diminished according
to the necessity of the moment.

B. The Anterior Chamber is the space between the cornea in front, and
the iris and lens behind. It is filled with a clear fluid, known as the aqueous
humor.

C. Tlie Vitreous Humor is a transparent, colorless, gelatinous mass, occupying
the portion of the ball back of the iris ; its principal function is to aid in bring-
ing rays of light to an accurate focus on the retina, and also to contribute to the
solidity of the eye.

i. The Retina is the nervous portion of the visual organ, and is the part on
which the pictures of external objects are received, and thence transmitted
through the optic nerve (D), to the brain. It is, in health, a very delicate, trans-
parent membrane, of a very highly complicated and intricate structure, in which

136

E. & J. BECK, PHILADELPHIA.

very minute nerve fibres from the optic nerve and cells form an important
part. Not all portions of the retina are equally sensitive, but at one point
only— the macula lutea, or yellow spot, (p), are sharp and distinct images
of objects formed, and, in order to obtain clear images, we instinctively direct
our eyes so that the rays coming from the object fall exactly on this sensitive
spot.

After having thus briefly considered the structure of the eye, a few remarks
on the part which it plays in producing distinct vision, may not be amiss.

The rays of light coming from any object on this earth are, in reality, diver-
gent, since only rays coming from an infinite distance are parallel ; practically,
however, all rays coming from objects 20 feet or more away may be considered
as parallel; those coming from objects nearer than 20 feet are divergent.

From an optical standpoint, and that one we have chiefly to consider, the eye
is but a camera obscura or dark chamber ; in principle, just the same as the one
employed by the photographer. The refractive media of the eye— cornea,
aqueous humor, lens and vitreous body— form the lens of the camera; the iris,
the diaphragm ; the interior of the eye, the camera itself; and the retina, the
sensitized plate. Since the cornea and aqueous humor, and the vitreous humor
are almost identical in refractive power, we can consider the refractive system
of the eye as a simple biconvex lens. Now, glancing at the cut, we see the
course of the rays of light from external distant objects till they fall on the
retina.

DIAGRAM OF NORMAL EYE.

The parallel rays coming from some distant object, fall on the cornea, pass
through the lens and are bent from their course so that they come to a focus on
the retina, where a distinct image is formed, and the visual impression conveyed
to the brain by the optic nerve.

It is evident, that rays coming from an object, say 20 feet away, and those from
an object 20 inches, cannot be brought to a focus at the same point by the same
lens, and so it would be with our eyes had we not the power of increasing or
diminishing the convexity of our lenses. This change is constantly taking place
without our knowledge, if our eyes be healthy, but that it actually does take
place is easily proven.

If a piece of netting be held 12 or 14 inches in front of the eyes, and the gaze
be fixed intently on some distant object, as long as this is clearly seen, the
meshes of the netting will be indistinct ; while if these be accurately seen, the
distant object is no longer clearly in view; in other words, in bringing our gaze
from the far to the near object there has been a change in convexity of our lenses,
this being greater for near and less for distant objects.

This power of changing the form of the lens by the action of the ciliary
muscle, is known as the "accommodation," while that of bringing the rays of
light to a focus on the retina is called the " refraction" of the eye.

R. & J. BECK, PHILADELPHIA.

137

This alteration in the curvature of the lens is shown in the cut, which rep-
resents a horizontal section of the anterior part of an eye, the left half of the
figure represents the eye when accommodated for distant objects ; the right
half, when adjusted for small print held as close as possible.

The conditions of the eye which necessitate the use of glasses in order to
obtain perfect vision are either those of imperfect refraction or accommodation.

In regard to the state of the refraction, or of the power of bringing rays of
light to a focus on the retina, all eyes may be classed under one of three heads :
Emmetropic or normal, Myopic or near-sighted, and Hypermetropic.

THE EMMETROPIC EYE.

EMMETROPIC EYE.

In the Emmetropic or normal Eye, the rajTs from a distant object are brought
to a focus exactly upon the retina, thus giving a distinct image without any
artificial aid.

In order to ascertain whether an eye be normal in respect to its optical per-
formance, certain tests are employed, similar to those given on pages 121-124. A
normal eye should be able to distinguish readily the letters of No. X at 10 feet,
or those of No. XX at 20 feet; this test determines the "acuity" of vision. The
condition of the accommodation must next be tested; this is done by finding
the nearest and farthest points at which type as No. 1 can be distinctly seen ;
this gives the " near" and " far" points.

The '"far" point remains fixed until about the 45th year, when it gradually
recedes. The "near" point, on the contrary, is changing constantly with the
advance of life. A child of 10 years should be able to read No. 1 as close as 2}

138 R. & J. BECK, PHILADELPHIA.

or 3 inches; a man of 21 years, at 3^ to 4 inches ; one of 40 years, at 8 or 9 inches,
while a person of 60 years will not be able to see print closer than 24 or 30
inches.

MYOPIA; OR NEARSIGHTEDNESS.

MYOPIC EYE.

It has already been stated that this defect depends upon the refractive condi-
tion of the eye ; it is that condition in which the rays from distant objects come
to a focus in front of the retina, and consequently the latter receives but the
blurred and indistinct image of external objects. A glance at the cut will ex-
plain this. Myopia is usually due to an abnormal lengthening of the eyeball,
thus causing the retina to recede from the point where the rays come to an ac-
curate focus. It is a disease which often exists from birth, and is frequently
hereditary ; but, although frequently this condition is present from birth,
and manifests itself in later life, no doubt, many cases are developed by
excessive use of the eyes at fine " near work," such as reading or sewing, before
the eoats of the eye have become fully developed and hardened. Statistics show
that the percentage of Myopia increases in proportion to intellectual develop-
ment, and, that while it may be quite small in the lowest grades of schools, it
steadily gains in numbers as the course of study becomes higher, until, in the
colleges aaid universities it reaches a very large percentage.

Among the prolific causes of the development of this disease, is the habit of
reading with the head bent forward and over the book, thus preventing the free
circulation of the blood, and causing a congestion of the eyes, which tends still
further to stretch the coats of the perhaps already weakened organ. The
habit of reading with insufficient illumination, or in a reclining posture, is also
most injurious,.

The popular belief that near-sighted eyes are strong ones is not only absolutely
incorrect, but also most mischievous, since there is no state of the eye which
more urgently demands the use of a proper glass, than does Myopia. Such eyes
instead of .being strong, are not only absolutely weak, but they are sick eyes,
and, if the defect be of a high degree, liable to the most serious accidents, which
may result in loss of sight. The danger lies not in the imperfect vision, but
in the interocular changes which accompany the defect in its higher grades, and
which often are progressive.

Myopic eyes are often very prominent ones, seeming too large for their
sockets. Indistinct distant vision, and in reading, holding the print close to the
eyes, are the chief symptoms of this defect.

The treatment of near-sightedness is the use of the proper concave glasses. By
this we hope to attain two objects. The rays are brought to a focus on the
retina, and thus distinct vision is insured ; and, by wearing the proper glasses, the
disease may usually be arrested. In cases where the defect is slight, the cor-

R. & J. BECK, PHILADELPHIA. 139

recting-glasses can be given by a good optician, care being taken to select the
weakest concave lens with which vision is normal ; where, however, the defect
is high, the advice of an oculist should be sought, who, after careful measure-
ment, will prescribe the proper glasses. These, with the strict observance of
the hygienic conditions in regard to posture and illumination, will usually
check the progress of the disease.

HYPERMETROPIA.

HYPERMETROPIC EYE.

This defect is dependent on a condition of the eye exactly the reverse of
Myopia. It is the condition in which the rays from distant objects come to a
focus behind the retina. A glance at the cut will explain this condition. Hyper-
metropia is due to a formation of the eye, which is present from birth. It is
also hereditary, being transmitted through entire families. Hypermetropic
eyes are usually flat and shallow in appearance.

Although present from birth, it is often, unless of a high degree, not mani-
fested until the duties of the school-room begin, and, in the slighter grades, it
may not be noticed until adolescence or middle-life; nevertheless, the defect
has existed all the while, but it has been masked and overcome by the exertions
of the little ciliary muscle. Distinct vision is one of the instincts of our senses,
and our eyes unconsciously adjust themselves so as best to secure it. As
we have before seen, any change of the convexity of the lens is effected by the
action of the ciliary muscle ; now, since the focus for the rays falls behind the
retina, the convexity of the leris of the eye m ust be increased in order to bring
the focal point on the retina, and hence the little muscle is called upon to do the
work ; but, since this condition of the eye is permanent, so also this muscular
contraction is almost constant while the eyes are employed. Besides this con-
stant exertion, the muscle must also act with vigor enough to give the ordinary
power of accommodation for near objects.

In youth the ciliary muscle is in its greatest vigor, and it then overcomes this
defect even when of considerable degree, but as age advances the power of the
muscles diminishes, and then it is that the defect begins to manifest itself.

The boy has passed through school without the slightest cause to suspect
himself the possessor of hypermetropic eyes ; college is entered, and increased
study is necessary. After reading for some time, he now experiences a sense
of fatigue about the eyes ; he stops and passes his hand across his closed eyes
for a few moments, then resumes his study ; after a few minutes the same is
repeated ; in a few months, he is, perhaps, troubled with headaches and pains
across the brow and above the eyes; these themselves feel heavy and ache
after the duties of the day, and so the symptoms progress until a half-hour's
study is purchased at the price of hours of discomfort.

In the higher degrees of Hypermetropia, reading, or other fine work, is
often impossible for periods of longer than a few minutes, the page becoming
misty, the letters running into each other, and everything appearing blurred.

140

K. & J. BECK, PHILADELPHIA.

The cause of all these symptoms is the overstrain and eventual exhaustion
of the ciliary muscle. So long as it is able to accomplish its excessive task,
it overcomes, or rather masks the defect, but as soon as its powers gives out,
the accommodation fails and indistinctness of near objects results, in addition
to which we have the long train of distressing symptoms which arise from
the overstrain ; many an obstinate headache has its source in an unrecognized
Hypermetropia !

Since in this state of the eye the focus falls behind the retina, the remedy
is found in a glass which will increase the refractive power of the eye, thus
bringing the focus of the rays of light on the retina: such a result is ob-
tained by the proper convex glass. As, however, the ciliary muscle is able to
mask a certain amount of the defect, even after it has become apparent, the
convex lens which most improves distant vision, will correct but the portion
of the Hypermetropia which is "manifest," and, indeed, frequently the patient
may reject all convex glasses as failing to improve his distant vision, and yet
be hypermetropic to a considerable degree.

The glass which corrects the manifest defect will often greatly conduce to
the patient's comfort, yet to select the glass which will correct the entire defect,
the accommodation of the eye must be temporarily suspended by putting the
ciliary muscle at rest by means of a solution of atropia, when the entire defect
becomes apparent and may be carefully measured by the oculist.

ASTIGMATISM.

Although this defect is very common, yet not until the last few years were it3
frequency and importance fully recognized. Astigmatism is a condition in
which the curvature of the cornea varies in the different meridians. On ex-
amining an ordinary lens we find that all parts of its surface have an equal
curvature, and so it should be in a normal cornea ; but in an astigmatic eye
it is not so, since the vertical curvature differs from the horizontal, thus pro-
ducing asymmetry of the refractive part of the eye, and, as a result, rays
falling on such an eye are not all brought to a single focus, but those in one
meridian fall either before or behind the retina, or focal point of the other
meridian, thus causing a confused and indistinct picture of the object viewed.
Astigmatism is either Myopic or Hypermetropic; it may also be "mixed" —
the eye being Myopic in one, and Hypermetropic in another of its meridians.

Vision in astigmatic eyes is usually impaired both for distant and near ob-

R. & J. BECK, PHILADELPHIA.

141

jects, since at no point can a distinct image be obtained ; but the distinguishing
feature of this defect is the fact that certain groups in a series of lines and
circles, such as represented in the figures on pages 136 and 137, are seen with
more distinctness and blackness than any others. Astigmatism has frequently

been discovered by looking at a clock, it being noticed that when the hands
were at certain figures, say III and IX they were seen with difficulty, while
when at VI or XII they were distinctly seen.

In the treatment of Astigmatism, recourse must be had to cylindrical lenses,
as the ordinary lenses would not correct the defect. Since the correcting
glasses for Astigmatic eyes are frequently combinations, these lenses are always
ground according to formula to correct the defect of each individual eye, which
can only be determined aftercareful measurement.

PRESBYOPIA.

Presbyopia, " far sight," or " old sight," is an accompaniment of the later
years of life; it is a physiological or natural, not an abnormal change, and
affects all eyes.

This condition depends almost solely upon the failure of the accommodation,
due to a gradual hardening of the lens and decrease of the power of the
ciliary muscle as age advances. Although this decrease in the power of adjust-
ment for near objects is not noticed until, perhaps, the 40th or 45th year, yet,
from the age of nine or ten, the accommodation is gradually growing weaker,
that is, fine print can no longer be seen as close to the eye as formerly.

As soon as the " near point" for small type passes beyond 8 inches, we con-
sider Presbyopia to have set in.

Difficulty in reading fine print or in threading the needle at night are among
the first symptoms usually noticed ; the page must be held further from the

142 R. & J- BECK, PHILADELPHIA.

eyes, and more strongly illuminated ; while small type is with difficulty seen.
These symptoms usually first show themselves at night, while reading or
working by artificial illumination, but gradually they manifest themselves like-
wise in the daytime.

All eyes undergo these changes producing Presbyopia ; we frequently, how-
ever, hear of persons, ripe in years, who have never felt the necessity of glasses
for reading or other fine work, and whose "strong" eyes are their especial
pride. Such persons have been near-sighted, probably, all their lives, their defect
neutralizing the normal changes taking place ; a weak concave glass before such
eyes will usually improve distant vision.

The popular opinion that the use of glasses should be postponed as long as
possible, is erroneous. As soon as unpleasant feelings denote the approach of
Presbyopia, glasses should be resorted to at once, as the longer the eyes are de-
prived of the aid which they need, and consequently are subjected to strain,
the more rapidly will the changes in the eye become developed.

The treatment of Presbyopia is found in convex glasses, of such strength
that fine print may be seen readily at 7 to 8 inches. Here such a glass is em-
ployed not to correct the refraction, as in the case of the convex lenses in Hyper-
metropia, but to aid the power of the eye in accommodating. Presbyopia, in a
perfectly healthy eye, does not affect the sharpness of distant vision, although
in extreme old age, distant vision also is somewhat diminished, owing to other
changes which affect the eye.

The glasses should be used at first only while reading by lamp or gaslight.
When the unpleasant sensations show themselves also in the daj^-time, then
the glasses previously worn at night should be used for reading by daylight,
and their place supplied by a pair of slightly stronger glasses for night-work.
In old persons, when distant vision is improved by weak convex glasses, those
of the proper strength may be worn constantly.

MUSCULAR AFFECTIONS.

Besides the defect depending upon refraction and accommodation, there is a
group of eye troubles caused by a want of harmony in the actions of the
various muscles by which the eyes are moved, some of which conditions are
greatly benefited by the use of a properly ground glass.

The most frequent condition giving rise to fatigue and weariness of the eyes
when used at near work, is that in which there is a want of balance between
the power of the muscles which move the eyes outwards, and those which draw
them together, the latter muscles being too weak to accomplish their task with-
out fatigue ; this condition is technically termed Insufficiency of the Interni.

Benefit is usually derived from wearing glasses on which are ground prisms,
with their bases turned towards the nose, by means of which the image is dis-
placed, it appearing to be further away, and consequently not requiring the eyes
to be converged to the same degree as without them. This condition is also very
frequently associated with one of the defects which we have already described ;
it is then aided by having the glass so ground as to combine the action of both
lens and prism.

When there is an absolute breach in the harmony between the muscles, we
have Diplopia, or double vision, produced ; two images of objects being seen,
owing to the pictures of the objects falling on dissimilar points of the retina of
each eye.

This condition usually is due to the failing of the power of one or more
muscles, and it often denotes very grave disease, situated in the brain or
nerves. Under such circumstances, it is evident that the treatment must ba

i

E. & J. BECK, PHILADELPHIA. 143

directed to the deep-seated cause of the disease, and that local means as applied
to the eye can only relieve, not cure.

When the double images are very marked, by wearing a shade or opaqno
glass over one eye, we obviate this very annoying symptom ; where the images
are but very slightly separated, the temporary use of a proper prismatic glass
will afford relief.

, TEST-TYPES.

The following " Test-Types" will enable persons to give inlormation that will
greatly assist us in supplying glasses suited to their sight : —

The paper should be held with a good light falling upon it: if by daytime, tho
person should place himself with his back to a window ; or if by artificial light,
with the full illumination falling on the page, but not on the Eyes.

Each eye to be tested separately.

PARTICULARS REQUIRED BEFORE SUPPLYING GLASSES.

What is the extreme distance in feet and inches at which you can read Test-
Types Nos. 1, 2, 4, 6, 10, 20?

What is the nearest distance in feet and inches at which you can read Test-
Types Nos. 1, 2, 4, 6, 10, 20 ?

Have you ever used glasses before ?

If so, did they make your eyes ache ?

Are the Spectacles required for Reading or Walking?

What is the distance from the centre of one pupil to the centre of the other,
(from A to B, Fig. 11, page 132) ; measure with a tape or rule across the nose.

Is the bridge of the nose prominent or not ?

AN ASCENT TO THE SUMMUT OF MOUNT BLANK.

No. 1.

An Assent to th* Sfummut of Mount Blank.— It was on the 1st of August— I remember by my wags oumming dew, and I wanted to be ri«,— that
Me and master maid our minds up to the Mounting. I find Master as oppend an acount .vith the Keep Sp«k— but as that is a cut abov. aud rit in by
only Lords and Laddies. I am redeuced to a Peer in the pagis of the Comick Anual — Mr H giving leaves.

Wile we waited at Sham Money, our minds sevral tims misgiv, but considdring only twelve tientlemen and never a footmun had bin up, we determind
to make ourselves particler. and so highered gides to sho us up. For a long tim the whether was dout full weather — first it anew — then thew — and
then friz — and that was most agreeabil for a tempting. The fisst thing I did was to change my blew and wite livry, as I guest we shood have enuf of
blew and wite on the mounting— but put on a dred nort for fear of every thing— takin care to hav my pokets well cramd with sand witches, and, as
proved arterwards, they broke my falls verry much when I slipd on my bred and urns. The land Lord was so kind as lend me His green gaws tap room
blind for my eyes, and I recumend no boddy to go up any Snowhill without green vales — for the hice dasls like winkin. Sum of the gides wanted me
to ware a sort of crimpt skaits,— but thoght my feet would be the stifer for a cramp on — and declind binding any think zoept my list garters round my
Shews. I did all this by advize of John Mary Cuthay the Chief Gide, who had bin 8 tims up to every think. Thus a tired we sit out, on our feat, like
Capting Paris, with our Nor poles in our hands —Master in verry good sperrits, and has for me I was quit ellivatted to think what a Jigger the Summut
■ef Mount Blank wood cut down the airy s of Portland Plaioe.

No. 2.

Arter sliping and slidding for ours, we cum to the first principle Glazier. To give a correct noshun,
let any one suppose a man in fustions with a fraim and glass and puttey and a dimond pensel, and
it's quit the revers of that. It's the same with the Mare of Glass. If you don't think of a mare or
any think maid of glass you have it xactly We was three ours gitting over the Glazier, and then
come to the Grand Mullets, ware our beds was bespoak — that is, nothing but clean sheats of sno, —
and never a warmin pan. To protect our heds we struck our poles agin the rock, with a cloath over
them, but it looked like a verry litle tent to so much mounting. There we was, — all Sno with us
Sollitory figgers atop Nothink can giv the sublime idear of it but a twelf Cake. The Gides pinted
out from hear the Pick de Middy, but I was too cold to understand Frentch — and we see a real
Shammy leeping, as Master sed, from scrag to scrag, and from pint to pint, for vittles and drink — but
to me it looked like jumpin a bout to warm him self. His springs in the middel of Winter I realy
beleave as uncredible. Nothink else was muving xcept Havelaunches, witch is stupendus Sno balls
in high situations, as leaves their plaices without warnin, and makes a deal of mischef in howses and
families. We shot of our pistle, but has it maid little or no noise, didn't ear the remarkably fine ekko.

144 R. & J. BECK, PHILADELPHIA.

No. 3.

"We dind at the Grand Mullets on cold foul and a shivver of am, with a
little 0 de Colon, agen stomical panes. Wat was moor cumfortble we
found half a bottel of brandey, left behind by sum one before, and by
way of return we left behind a little crewit of Chilly Yiniger for the
next cummer, whoever he mite be or not After this repass'd, we went
to our subblime rests, I may say, in the Wurld's garrits, up 150 pare of
stares. As faling out of Bed was dangerus, we riz a wal of stons on
each side. Knowing how comfortble Master sleeps at home, I regretted
his unaccommodation, and partickly as he was verry restless, and evry

No. 4.

tim he stird kickd me about the Hed. I laid awack
a good wile thinking how littel Farther, down in
Summerset Sheer, thoght I was up in Mount Blank
Sheer ; but at long and last I went of like a top, and
dremt of Summuts. Won may sleep on wus pillers
than Nap Sacks. Next mornin we riz erly, having

No. 5.

still a good deal to git up, and skrambled on
agin, by crivises and crax as maid our flesh
crawl on hands and nees to look at. Master
wanted to descend in a crack, but as he mite not
git up in a crack agin, his letting himself down

R. & J. BECK, PHILADELPHIA. 145

No. 6.

was unrecomended. Arter menny ours
work, we cum to the Grand Plato. Mas-
ter called it a vast Amphi-Theater ; and
so it is, except Du-Crow and the Horses
and evry thing. Hear we brekfisted, but

No. 7.

was sirprizd at our stomicks
not having moor hedges, Mas-
ter only eting a Chickin wing,
and me only eting all the rest.

No. 10.

We had littel need to
not eat, — the most
uneasy part to go

146

R. & J. BECK, PHILADELPHIA.

GQ

A

o

Pi
<

n
n

00

£0

R. & J. BECK, PHILADELPHIA.

147

TO OCULISTS.

Having unsurpassed facilities for the careful and accurate filling of prescrip-
tions of all characters, at the shortest notice, and at prices much more reasonable
than those heretofore prevailing, we solicit the same of you, with our guarantee
of giving perfect satisfaction.

We glaze cylindrical and prismatic lenses to Eye-glass frames of any form,
and in order to allow your patients at a distance to choose what may suit their
fancy, will send by mail several pairs for selection.

We will also furnish to Oculists blank prescription papers as below, which
will merely require filling up with the figures of the formula and name of the
patient.

Philadelphia,

.18

PRESCRIPTION FOR SIGHT.

For

^tospboiWbd^

«*3M

^ 70 ep so ioo m 1?0

R.=

L.=

o

2

Q
<

W

K

R.=

L.=

148

E. & J. BECK, PHILADELPHIA.

No. 2011.

No. 2015.

R. & J. BECK, PHILADELPHIA. 149

No. Prick

2000. The Human Eyeball, Enlarged Size, the upper portion of
which (containing a microscopical representation of the layers of
the retina,) is to be taken off, when the cornea and iris, the lens
and the vitreous body may be taken out, $0 50

2005. Dr. Perrin's Model of The Eye, for the practice and study of
the Ophthalmoscope, with twelve colored shells, representing nor-
mal and diseased conditions of the eye, as seen with that instru-
ment. Packed in handsome Morocco case, 25 00

2010. Liebreich's Ophthalmoscope, with two convex condensing
lenses, and a series of five lenses of different foci, fitted to an
arm behind the perforated mirror ; in Morocco case, . . . 6 00

2012. Dr. Knapp's Ophthalmoscope, with two mirrors, 1£ inches in
diameter, with revolving disc containing fifteen lenses, eight
convex from 2 to 48 inches focus and seven concave from 4 to 48
inches focus, with condensing lens ; in Morocco case, . . . 17 50

2014. Beok's Improved Adjusting Binocular Ophthalmoscope, in

fine Morocco case, 32 50

2015. Loring's Ophthalmoscope, with mirror 1J inches in diameter, and

revolving disc at back containing twelve lenses, six each convex
and concave, of 3, 5, 8, 12, 18, 36 inches focus; double convex
condensing lens 1\ inches in diameter in hard rubber frame ; in
Morocco snap case, 14 00

2016. Loring's Ophthalmoscope, similar in form and size to No. 2015,

with one mirror and one condensing lens, and a series often con-
vex and eleven concave lenses of the Dioptric System, set in a
revolving disc, covered with metal to preserve them from dust, . 17 50

2017. Loring's Ophthalmoscope, similar in size and form to the pre-

ceding, but with two mirrors, two condensing lenses of 2i and 3
inches focus, and three revolving discs containing a series of
twenty-three lenses, convex and concave, from 2 to 60 inches

focus, of the Inch System, 20 00

2017*. Loring's Ophthalmoscope, the same as 2017, with the addi-
tion of a rectangular mirror, swung on two pivots, to tilt both
ways to angles of 20° or 25°, which can be readily substituted for
the ordinary circular mirror ; in snap Morocco case, . . . 25 00

2018. Loring's New Ophthalmoscope, in Morocco Case, . . . 35 00

This instrument consists of a disc, and a quadrant of a disc carry-
ing the lenses.
The single disc contains sixteen glasses on the metric system, the plus being
numbered in white, and the minus in red. The first row of numbers, or that
just beneath the glass, shows the real value of the glass; the second or inner
row shows the result of the combinations when the quadrant is in position. The
quadrant rotates immediately over the disc and around the same centre, and
contains four glasses, — 5 — 16, and -{-5-J-16. When it is not used the quadrant is
beneath its cover. The instrument then represents a simple Ophthalmoscope
with sixteen perforations, the series running with an interval of I D, and ex-
tending from I to 7 plus, and from I to 8 minus. This is ample for all ordinary
work, as the interval of I D, is as close as even an expert usually desires, and
can, with a little experience, be used for even very minute discrepancies. For
if in a given case the fundus is seen distinctly with I D and a little to spare,
while 2 D blurs the picture, we know at once that the refraction must be between
the two, or I 5 D. If, however, for any reason we wish to prove this conclusion,
we can bring up 0 5 D. From this glass we get successive half-dioptic from. I to

150

B. J. BECK, PHILADELPHIA,

8 plus, and from I to 9 minus. In this way we have, so to speak, a fine and
coarse adjustment, as in the microscope. If the higher numbers are desired,
these are obtained by combinations with those of the quadrant. These progress
regularly up to 16 D, every dioptric being marked upon the disc ; above this, up
to -J-23 D and — 24 D, we have to simply add the glass which comes beneath the
16 D, turning always in the same direction.

The mirror shown in the drawing is the "tilting" form. If preferred, the
common circular mirror can be employed.

2019. Dr. Thomson's Ameteometee, in Morocco Case, .... $11 00
This instrument, as shown in the illustration, consists of a small fixed gas-jet
A, a second one B, attached to a box C, which slides upon a bar D, the jets con-
nected by a flexible rubber tube G ; the end of the bar F forms a pointer, which,
by elevating or depressing the other end of the bar, can be placed at any part of
the graduated half-circle E, which is fixed firmly to the thimble H, by which
means the entire instrument can be attached to a common gas-burner, and the
lights regulated by its stop-cock.

The jets having been lighted and turned down into two small flames about 5
mm. in diameter, the patient, placed 5 metres away, is directed to observe the
flames, and to say whether he sees them as small points of light separated, or as
diffused'enlarged circles, which can be made to come in contact at their margins
by sliding movements of the box on the bar, by the hand of the surgeon ; bear-
ing in mind that an emmetropic or corrected ametropic eye will resolve the
lights into two until they pass, one behind the other, and become fused, whilst
in ametropia the circles will seem to touch ; whilst a distance, depending upon
the degree of ametropia, remains between the small light points. To determine
the kind of ametropia, the patient is directed to pass slowly in front of the eyo
under examination a slip of red glass in such a manner as to color half of each
diffused circle, and if the red half seems to be on the same side with the red

It. & J. BECK, PHILADELPHIA.

151

2019.

glass, myopia is recognized, and if on the other side, hypermetropia ; this may
be as well done by passing before the eye a card or paper in such manner as to
exclude from view one-half of each circle.

To determine the degree of ametropia, the bar has been divided on one side
into spaces of 2.5 cm. with a half space between, and on the other into English
inch and half-inches, and it will be found that each space of 2.5 cm. will indicate
an ametropia of one dioptric, metric system, and each inch ^ of the old system.
The cut represents the two flames as apart 2 d., and they would appear to a per-
son having M. or H. of 2 1). or ^ as two circles of light, with their margins in
contact at one point, separating on the removal of light B, and overlapping when
it is placed nearer to light A.

For those who prefer the old system to the metric, it will be remembered that
the old glasses are not based upon their exact powers of refraction, but are
ground on radii of Paris inches, and that, owing to the index of refraction of
the glass commonly used, they by a happy chance correspond in focal length
almost exactly with the English inch ; hence, each inch of distance between the
test-lights as determined by the use of the inch scale on the bar, will indicate an
ametropia of very nearly ^ ; and the higher degrees can be found instantly by
dividing 40 by the number of inches between the lights when their margins
seem to have come into contact.

When astigmatism is suspected, the patient should be directed to observe
whether the flames are longer in one direction than the other, and if so, by the
rotation of the bar on a pivot opposite to light A, the two lights being placed
some distance apart so fehat they do not appear to touch, we have one of the most
accurate means of ascertaining the meridians of greatest and least refraction,
since it will become easy for the patient to say when two elongated points or
ovals of light are placed so as to have the same direction ; and when this has been
fixed, the pointer F will indicate on the half- circle the exact angle at which the
lights are placed, and hence the position of the meridian of greatest ametropia.

On bringing the flames into contact at this angle, the real distance of the lights
apart will indicate the degree of ametropia, and having thus found one meridian,
the lights can be placed at right angles to it and the refraction of the second be
ascertained. In difficult cases, or with poor observers, it may be an aid to color
one of the flames by placing a slip of red glass in front of it.

152

R. & J. BECK, PHILADELPHIA.

TRIAL SIGHTS.

No. 2020.

No.

2020.

2021.

2022.

2023.

Prior

Nachet's Complete Series op Trial Sights, comprises 32
pairs each of Spherical convex and concave lenses from 2 to 72
inches focus ; 19 pairs each of plane Cylindrical convex and con-
cave lenses from 6 to 60 inches focus ; 9 Prisms, of angles from 2
to 10 degrees; 4 plane colored glasses ; 1 white glass disc; 1 half-
ground surface ; 2 metal discs, with stenopaic slit ; 1 metal disc,
with hole, and one ditto solid; I adjustable spectacle frame with
revolving graduated fittings for holding the various lenses ; and
one ditto not graduated. The whole packed in a first-class Mo-
rocco-covered or Rosewood case, with lock, $110 00

Nachet's Series of Trial Sights, the same in all particulars as
2020, excepting the cylindrical lenses, which are single and not in
pairs,

Series op Trial Sights, mounted and packed precisely the same
as Nachett's, Set No. 2021, containing the same number of lenses,
spherical and cylindrical, with two adjustable trial frames, one
graduated to 180° (No. 2030), in Rosewood case,

Series of Trial Sights, mounted the same as the preceding,
consisting of 27 pairs each of spherical convex and concave lenses
from 2 to 72 inches focus ; 12 each convex and concave cylindrical
lenses, from 8 to 60 inches focus ; 7 prisms of angles from 2 to 10

90 00

85 00

R. & J. BECK, PHILADELPHIA.

153

No.

Price.

degrees ; 3 plane, colored glasses ; 1 white glass disc ; 1 half-ground
ditto ; 1 metal disc with hole in. centre ; 1 ditto with stenopaic slit,
and one adjustable trial frame, No. 2030; the whole packed in a
Morocco covered case, with clasps, $70 00

2024. Series of Trial Sights, consisting of 23 pairs each of spherical

convex and concave lenses, from 2 to 72 inches focus; 12 each cyl-
indrical convex and concave lenses, 8 to 60 inches focus ; 6 prisms
2 to 10 degrees ; 2 metal discs ; 1 plane glass ; 1 ground glass, all
mounted in neat metallic frames; 3 colored glasses, and a gradu-
ated frame for holding the various lensns ; the whole packed in a
fine Morocco covered case, 60 Oo

Any of the foregoing Series of Trial Sights can be furnished in either the dioptric
or inch system of numbering.

2025. "Our Own", Complete Series op Trial Sights, comprises 30

pairs each of spherical convex and concave lenses from 0.25 to 20
Dioptric ; 18 pairs each of cylindrical convex and concave lenses
from 0.25 to 6 Dioptric, 10 prisms of angles from 1° to 12°; 4 plane
Colored glasses ; 2 metal discs with stenopaic slits ; 2 metal discs,
with holes, and one ditto solid, with new adjustable and graduated
spectacle frame for holding the lenses, No. 2027. The whole
packed in an elegant solid Mahogany case, with detachable lid

and lock, 110 00

The above series of Trial Sights are the most perfect and reliable ever made,
and are recommended by us as Standard. Each lens receives the most rigid
scrutiny before leaving our works, and is guaranteed to be absolutely correct.
The new Trial Frame is altogether the best ever made.

No. 2027.

2027. " Our Own", Graduated Adjustable Trial Spectacle Frame.
This instrument in which the Trial Sights are placed in grooves,
with graduations for the cylindrical lenses, is placed on the head
like an ordinary pair of spectacles, and has adjustments for deter-
mining the distance between the centres of the eyes, and the
height of the bridge of the nose,

20i8. " Our Own", Graduated Adjustable Trial Spectacle Frame,
the same in all respects as No. 2027, excepting the sides or temples,
which are made to hook behind the ears and have sliding adjust-
ment for distance from front of face,

10 00

12 50

154

No.

E. & J. BECK, PHILADELPHIA.

Price.

No. 2030.

»
2030. Trial, Spectacle Frame, with double grooves to each eye, gradu-
ated to 180°. Any desired combination of spherical and cylindri-
cal lenses can be adjusted in a moment to this frame, and given to
the patient for trial, . $5 00

No. 2032.

No. 2032.

2032. Artificial Human Eyes of very superior make, and in every
variety of size and color. Carefully fitted to any case,
Liberal discounts to Oculists.

10 00

No. 2033.

2033. Adjusting Cone, for Measuring the Distance between the
Eyes. Holding the instrument in the right hand, a distant object
should be looked at with the right eye through the hole in the

E. & J. BECK, PHILADELPHIA. 155

No- Price.

right hand cone; the other cone, fixed to an adjusting arm,
should be moved backwards and forwards until the left eye sees
the same object through the aperture in the left cone, and the two
holes appear as one. The distance between the eyes is then indi-
cated on the cross bar, one side of which is divided to inches and
tenths, the other to millimetres, $5 00

2035. Dr. Thomson's Metal Discs, for determining the degrees of

Ametropia, 4 00

£037. Trial Glasses, Hard Rubber Frames, 5 to 48 inches focus.

Convex, 12 0J

2038. Trial Glasses, Hard Rubber Frames, 5 to 48 inches focus.

Concave, 13 CO

2040. Green's Test Diagrams, for the detection of Astigmatism. This

set consists of a card-board dial 12 inches in diameter, divided
into 12 equal parts as in a clock dial, to which can be attached
separately a series of 14 diagrams of lines and circles made to
revolve at pleasure against the face of the dial, . . . . 5 00

2041. Snellen's Series of Test Types, bound in paper, . . . . 2 00

2042. Dr. Oliver's Color Sense Measurer. This contrivance con-

sists of a perforated disc, which can be so regulated by the rotation
of a series of cards, and the movement of a graduated slide as to
expose known areas of colors, 3 50

GOLD SPECTACLES.

Fitted with First Quality only of Double or Periscopic Convex or Concave
White, or Plane Blue or /S'mo&e-colored Glasses.

SINQLE TEMPLES.

Nos. 2050-2055.

2050. Single Temples, 8 karat, per pair, . . . . . . . .$>...,

2051. " " 10 " " 6 00

2052. " " 12 " " 7 50

2053. " " 14 " " 9 00

2054. " " 16 " " H 00

2055. " " 18 " " 12 00

15G

R. & J. BECK, PHILADELPHIA.

GOLD SPECTACLES.

HOOK TEMPLES.

Nos. 2056-2058.

No. PkiCB'

2056. Hook Temples, 10 karat, very light, $5 00

2057. " " 14 " " 6 00

2058*. " " 16 " " 8 50

HOOK TEMPLES (FRAMELESS).

No. 2060.

2060. Hook Temples, frameless,

?6 00

R. & J. BECK, PHILADELPHIA.

157

GOLD SPECTACLES.

SLIDING TEMPLES.

Nos. 206-1-2068.

No. ,

2064. Sliding Temples, 10 karat, per pair,

2065. " " 12 "

2066. " " 14 "

2067. " " 16 "

2068. " " 18 "

Pthce.
$9 00

10 00

11 00
13 00
15 00

COIN SILVER SPECTACLES.

Fitted with First Quality only of Double or Periscopic Convex or Concave

White Glasses.

SINGLE TEMPLES.

Nos. 2070, 2071.

2070. Single Temples per pair, . • • • • ; • $2 50

207i# " « fitted with divided glasses for reading and distant

vision, ... . • • • •

3 50

158

E. & J. BECK, PHILADELPHIA.

COIN SILVER SPECTACLES.

SLIDING TEMPLES.

Nos. 2072-2073.
Ko. Price.

2372. Sliding Temples, per pair, . . . $3 00

2073. " " fitted with divided glasses for reading and distant

vision, 4 00

ARUNDEL TINTED SPECTACLES.

Fitted with First Quality only of Arundel Tinted, Periscopic Convex or Con-
cave Glasses.

SINGLE TEMPLES.

No. 2075.
2075. Single Temples, Finest Steel Frames, $2 00

ELASTIC STEEL SPECTACLES.

Fitted with First Quality only of Double or Periscopi« Convex or Concave
White Glasses.

SINGLE TEMPLES.

Nos. 2080-2083.
2080. Finest finished Steel Frames, per pair, * $2 00

K. & J. BECK, PHILADELPHIA.

No.

11081. Fine Finished Steel Frames, per pair,

2082. Medium " " " «

2083. " " " " fitted with divided glasses fcr read-

ing and distant vision, . .

159

Price.
$1 50

1 00

2 00

PULPIT SPECTACLES.

Fitted with First Quality only of Double or Periscopic Convex or Concave
IVliite Glasses.

SINGLE TEMPLES.

No. 2085.

2085. Finest Finished Steel Frames, per pair, $2 00

This form of Spectacle Frame *c very convenient for public speakers who are
obliged to use glasses in reading their notes; as the top being nearly straight
allows the wearer to look over it when the eyes are directed toward the audience.

INVISIBLE SPECTACLES.

Fitted with First Quality only of Double or Periscopic Convex or Concave
White Glasses.

HOOK TEMPLES.

No. 2086.

208">. Finest Finished Hook Temples, of Steel; the frames set in a

groove in the glasses, almost invisible, . . . . . $2 50

2087. Finest Fini&hed Heck Temples, of Steel, . • • • . . $2 50

160

K. & J. BECK, PHILADELPHIA.

FRAMELESS SPECTACLES.

Fitted with First Quality only of Double or Periscopic Convex or Concave
White Glasses.

HOOK TEMPLES.

No.

No. 2088.
2088. Finest Finished Steel Hook Temples, .

EYE-PK0TECT0RS.

Price.
§2 50

Nos. 2090-2092.

2090. Coquille Spectacles, with large egg-shell shaped glasses, either

blue or smoke color, for protecting the eyes against an intense
glare of light, or from dust. Steel Frames, light Hook Temples,

2091. Coquille Spectacles, Medium Finish, Single Temples

2092. '* « Ordinary " " " . .

2093. Miller's or Turner's Spectacles, strong frames and large

plane white glasses, to guard the eyes against chips, etc.,

2 00

1 00

75

50

Kos. 2095-2096.
2095. Wire Gauze Eye-Protectors, with Plane Green, Blue, Smoke

No.

K. & J. BECK, PHILADELPHIA.

or White Glasses, and Steel Temples, as in ordinary Spectacles ;
finest finished frames and glasses.

2096. Wire Gauze Eye-Protectors, similar in style to No. 2095, but

with medium finished frames and glasses,

2097. Wire Gauze Eye-Protectors, similar in form and style to No.

2095, but with frames and glasses finished in a more ordinary
manner, .

2098. Wire Gauze Eye-Protectors, similar to the preceding, but

fitted with an elastic band in place of the steel temples, .

2099. Eye-Shades, with light wire frame fitting on the head like a cap ;

for both eyes or for one,

101

Pricb.

$2 00
1 50

75

50

35

All the Spectacles herein described are furnished with a handsome leather
case, without charge, and any of the frames will be fitted with plane green, blue
or smokc-coiored glasses, at the prices given.

GOLD EYE-GLASSES.

Fitted with First Quality only of Double or Periscopic Convex or Concave
White Glasses.

Nos. 2100-2105.

2100. Compound Spring Pattern, 8 karat, $5 00

2101.
2102.
2103.
2104.
2105.

i U

10 "

i tl

12 "

i ff

14 "

< H

16 "

4 44

18 "

5 50

6 50

7 £0
9 00

10 00

1G2

R. & J. BECK, PHILADELPHIA.

GOLD EYE-GLASSES.

Nos. 2106-2111.

No. Price.

2106. Anatomical Pattern, 8 karat, $5 00

2107. " 10 " 6 00

2108. " " 12 " 7 00

2109. " " 14 " 8 00

2110. " " 16 " 10 00

2111. " " 18 " . . 12 0Q

No. 2112.

2112. Frameless, with 14 karat Spring and Handle,

$6 00

R. & J. BECK, PHILADELPHIA,

163

ARUNDEL TINTED EYE-GLASSES.

Fitted with First Quality only of Arundel Tinted Double or Periscopic Convex
or Concave Glasses.

No.

No. 2115.

Piuce.

$2 00

2115. Arundel Pattern, very comfortable,

These glasses, together with the Arundel Tinted Spectacles, No. 2075, are
fitted with slightly tinted glasses, so graduated, that the tint remains of the
same density in all foci. They are particularly agreeable for reading by arti-
ficial light, and a great help to weak eyes. Being very carefully made and
finished they are the handsomest and most desirable of all steel-framed Glasses.
If desired they can be furnished in Gold, Shell or Hard Rubber frames.

STEEL EYE-GLASSES.

Fitted with First Quality only of Double or Periscopic Convex or Concave
White Glasses.

No. 2120.

2120. Anatomical Pattern,

*1

164

B. & J. BECK, PHILADELPHIA.

STEEL EYEGLASSES.

No. 212L

No.

2121. Compound Spring Pattern,

2122. * " ,"

very light grooved glasses, •

Price.

$2 00

250

No. 2123.

2123. Frameless Pattern, with Steel Spring and Handle, .

. f 1 50

All of our Steel Eye-glass Frames are of the lightest possible weight, but so
exquisitely tempered as to be much stronger and more durable than those
usually sold. They are furnished either blued or of the light bronze or straw-
color now so much used, as may be desired.

E. & J. BECK, PHILADELPHIA.

165

SHELL EYE-GLASSES.

Fitted with First Quality only of Double or Periscopic Convex or Concav

White Glasses.

2127. Anatomical Pattern,

166

E. & J. BECK, PHILADELPHIA.

HARD RUBBER EYE-GLASSES.

Fitted with First Quality only of Double or Periscopic Convex or Concave
White Glasses.

2130. Anatomical Pattern,

All the foregoing Eye-glass Frames will be fitted with either plane blue or
smoke-colored glasses, and furnished with a case and silk guard, without
increase of cost.

R. & J. BECK, PHILADELPHIA. 167

SPHERICAL SPECTACLE LENSES.

Spherical, Cylindrical or Prismatic Lenses, of the First Quality only fitted to
frames at the following prices :

No. Price.

2135. Periscopic or Double Convex White Lenses, from 5 to 72 inches

focus, per pair, = 75

2136. Periscopic or Double Convex White Lenses, from 1 to 4f inches

focus, per pair, . $1 25

2137. Double Convex White, Divided or Franklin Lenses, per pair, . 1 50

2138. " " " Lenses, two foci on one glass, " . . 1 50

2139. Periscopic or Double Convex Tinted Lenses, Blue, Pink, Green

or Smoke, per pair, 1 50

2140. Periscopic or Double Concave White Lenses, from 5 to 72 inches

focus, per pair, 75

2141. Periscopic or Double Concave White Lenses, from 1 to 4| inches

focus, per pair, 1 25

2142. Periscopic or Double Concave Tinted Lenses, Blue, Pink, Green

or Smoke, per pair, 1 50

2143. Plane, Blue, Green or Smoke-colored Glasses, per pair, . . . 1 00

CYLINDRICAL SPECTACLE LENSES.

2145. Piano-Convex or Concave Cylindrical White Lenses, per pair, . 2 00

2146. " " " " " single lens, . 1 25

2147. Sphero-Convex " " " " per pair, . 4 00

2148. " " " " " single lens, . 2 50

2149. Plano-Oonvex or Concave Cylindrical and Prismatic White

Lenses, per pair, . . . . . . . . . . 4 00

2150. Piano-Convex or Concave Cylindrical and Prismatic White

Lenses, single lens, 2 50

2151. Sphero-Convex or Concave Cylindrical and Prismatic White

Lenses, per pair, 5 50

2152. Sphero-Convex or Concave Cylindrical and Prismatic White

Lenses, single lens, 3 00

2153. Crossed Cylindrical Lenses, Convex or Concave, White, per pair, . 7 00

2154. " " " " " " single lens, 4 00

PRISMATIC SPECTACLE LENSES.

2160. Plane Prismatic Lenses, White, per pair, 2 00

2161. " " " single prism, 1 25

2162. Sphero-Prismatic " " per pair, 4 00

2163. " " " single prism, 2 50

PEBBLE SPECTACLE LENSES.

2165. Periscopic or Double Convex Pebble Lenses, per pair, . . . 3 00

2166. " " Concave " " " ... 3 00

163

R. & J. BECK, PHILADELPHIA.

SPECTACLE AND EYE-GLASS CASES.

No. 2170.

No. 2171.

No. 2173.

Nos. 2175-2176.

Price.

20

20

75

50 to 1 50

1 25 to 1 75

No. 2181.

No.

2170. Spectacle Case, Morocco, -with tuck, • • • •

2171. " " " open end, ....

2172. " " Fine English Leather, ....

2173. " " Scotch Plaid Frog Mouth, .

2174. " " German Silver, Plated,

2175. Velvet Chatelaine Case . 1 00 to 3 00

2176. Morocco " " 75 to 2 00

2180. Eye-Glass Case, Morocco, open end, ....... 15

2181. " " Finest Russia Leather, 35

2182. " Hooks, Gold, 1 50 to 5 00

2183. " " Gilt, 25

2184. " " Steel 15

2185. " Chains, Gold, with Hook, v 4 00 to 6 50

2186. " Guard, Pure Silk, 10

2187. " " Catgut, 10

R. & J. BECK, PHILADELPHIA.

169

NICOL'S PRISMS.

No.

Prick.

$2 25

2 75

3 50

4 00
4 75
6 75
9 75

20 00

2200. Nicol's Prism of Iceland Spar, 8 millimetres across face,

2201. " " 9 "

2202. " " 10 "

2203. " " 11

2204. " " 12 "

2205. " " 14 "

2206. " " 16

2207. " " 20 "

Larger sizes imported to order.

CLAUDE LORRAINE, or LANDSCAPE MIRROR.

Claude Lorraine, or Landscape Mirror. A pleasing and beautiful instrument,
for viewing clouds, landscapes, etc. As the mirror condenses or diminishes the
view into a true perspective effect, the instrument is invaluable to the artist,
and a very desirable companion for tourists. Six sizes, as follows :
2220. MiRROR,6i inches longby5i inches wide,in strong morocco case, each,

2221.

2222.
2223.
2224.
2225.

2230.

2231.
2232.
2233.
2234.
2235.

2238.
2239.

71
7i

91

5£
6i
6i
7i

71

2245.
2246.
2247.

2248.

HAND MIRRORS, IN BLACK WOOD FRAMES.

Mirror Magnifying on one side, diminishing on the other, 6 inches
diameter,

Mirror, Cylindrical (elongating and shortening), 6 inches diameter,
Multiplying (producing several images), 6 inches diameter,
Magnifying on one side, plane on the other, 31 in. diameter,

(< << <( it ft (<

a it (< it n a

HAND MIRRORS, IN FINE MAHOGANY FRAMES.

Mirror, Magnifying on one side, diminishing on the other, 5 inches
diameter, :

Mirror, Magnifying on one side, diminishing on the other, 6 inches
diameter,

MAGIC LANTERNS.

In Japanned Tin, with Coal-Oil Lamps.
Magic Lantern, 6 inches high, with 6 glass and 3 movable slides,

<< it n tt "6 "3 " "

u it g u "6 "3 " ll

a u q ii "6 "3 " "

KLAEGER INSECT PINS.

5 50

6 00

7 50
9 00

10 00

11 00

5 00
3 00
5 00

1 75

2 50

3 00

3 00

4 00

5 00

6 00

7 50
9 00

2250. The Genuine Klaegee Insect Pins, five sizes, per 100, . . 15

" 1000, . 1 25

2255. Zoetrope, or Wheel op Life, . 3 00

A mechanical and optical exemplification of the persistence of vision, and a

valuable aid in illustrating the wonders of optics. The turning of the drum or
cylinder brings into view the varying form or position of a figure in rapid
succession, until they blend into a perfect image full of motion and natural action.

2256. Extra views for Zoetrope, per set of six, 1 00

2260. Parlor Kaleidoscope, on Stand with Brass Front, . , . 2 00

170

K. & J. BECK, PHILADELPHIA.

WALKER'S AMATEUR PHOTOGRAPHIC OUTFIT.

No.
2300.

No. 2300.

Walker's Complete Amateur Photographic Outfit, .
This outfit comprises a/Camera complete with Achromatic Lens,
ground focusing glassS in frame, 2 Diaphragms, and Folding
Tripod with Walker's/Tripod Head.

1 "
1
1
1

1

Price.
$12 50

Walker's Patent Hard Rubber Double Plate Holder.

Light-tight Box for storing 24 Plates or Negatives.

Ruby Developing Lamp. Proto-Sulphate of Iron, ilb.

Copper Develop^ig Tray. Hypo-Sulphite of Soda, lib.

Graduating Glass. 2-oz. Bottle Intensifier.

Oxalate of Potash, £ft>. 2 Camel's Hair Brushes.

1 Book of Instructions.

12 Gelatine Bromide Dry Plates.
The above Outfit comprises all that is necessary for making Negatives. The
Chemicals are sufficient tf or developing 100 Negatives.
The requirements fort making prints from negatives are as follows :

2302. 1 Printing Frair/e, , 60

2303. 1 2-oz. Bottli Negative Varnish 50

2304. 1 2-oz. Bottle Permanent Toning Bath, sufficient for toning 800 to

1000 prints, /.,... 100

2305. Permanent Silvered Albumen Paper, cut to proper size for Pocket

Camera Negatives, per doz., 15

EXTRAS.

3 25
2 25
2 25

,35
30
65
25
25
10
10
65
30
10
65

4 50

2310. Extra Hard-Rubber Double Plate Holders,

2311. Drop Shutter for Instantaneous Views, ....

2312. Extra Lens and Mount, for near and small objects,

2313. Light-tight Boxes, for storing 24 plates or negatives, each,

2314. Copper Developing Pans, each,

2315. Ruby Developing Lamp,

2316. Graduating Gl4ss,

2317. Spirit Level,

2318. Proto-Sulphay of Iron, ^lb

2319. Hvpo-SulphitW of Soda, ^lb

2320. Oxalate of Potksh, $fl>

2321. Prepared Intewsifier, 4-oz bottle

2322. Sensitized BldelPaper, for Proofs, 'p doz.

2323. Gelatine Bronji&e Dry Plates, ...... f* doz.

2324. Leather Poubne .
The Leather flPqjicftes are for carrying Camera, Developing Pan, Graduating

Glass, Ruby Lapntifana Chemicals. These pouches are for tourists who can thus
carry everything necessary for developing in one package on the hip as a field-
glass is carried. I

The Hard Rubber Double Plate Holders are superior to any heretofore pro-
duced, as the frames are in onepiece. The material is non-absorbent, unaffected
by moisture and temperature, and therefore adsolutely light-tight. They are
very light, perfectly accurate and uniform in size and elegant in appearance. A
half-dozen can be stowed away in one's pockets with ease.

The whole apparatus is guaranteed to bepractical and perfect in every particu-
lar. The workmanship is of the best throughout.

-*""S. P. C.' -:-

FERRO. PRUSSIATE PAPER.

OUTFITS FOR 4X5 PICTURES.

1 4x5 Printing Frame.

1 4£x5£ S. P. C. Vulcanite Pan.

3 Dozen 4x5 S. P. C. Ferro Prussiate Paper

2 " sheets 6£x8£ Card Board.

1 Glass Form (for trimming prints. )
1 Robinson's Straight Trimmer.
a Pint Jar Parlor Paste.
1 1 inch Paste Brush.

I^E OOMPLETE, $25.80
Securely packed in a Paper Box.

'— S. P. C.i—

Ferro Prussiate Paper Outfit for 5 x 8 Pictures.

1 5x8 Printing Frame. 1 Glass Form (for trimming prints.]

2 Pint Jar Parlor Paste.

1 5x8 S. P. C. Vulcanite Tray.
3 Dozen 5x8 S. P. C. Ferro Prussiate Paper.

2 " sheets 9x11 Card Board.

1 l-£- inch Paste Brush.

1 Robinson's Straight Trimmer.
PRIOE OOMPLjEITE, $3.SO
Securely packed in a Paper Box.

3# 3P# v#

Sensitized Albumen Paper Outfit for 4x5 Pictures.

1 4x5 Printing Frame,

1 5x7 Porcelain Pan Deep.

1 5£x4J S. P. C. Vulcanite Tray.

2 Dozen 5x8 S. P. C. Sensitized Albumen

Paper.

1 Bottle French Agotate, / „

r tor toning

1 Lb. Hyposulphate of Soda.

2 Dozen sheets 6£x8^ Card Board with Gilt

Form.
1 ^ Pint Jar Parlor Paste.
1 1| inch Bristle Brush.
1 Glass Form (for trimming prints.)
1 Robinson's Straight Trimmer.

1 " Chlo. Gold, 1\ grains
1 2 Ounce Graduate.

PRIOE OOMPLiETE, $4.75
Securely Packed in a Paper Box.

+ i S. P. C. i—

Sensitized Albumen Paper Outfit for 5 x 8 Pictures.

1 5x8 Printing Frame.
1 7x9 Porcelain Pan Deep

1 5^x8^ S. P. C. Vulcanite Tr»y.

2 Dozen 5x8 S. P. C. Sensitized Albumen

Paper.
1 Bottle French Agotate j „

1 •• Chlo. Gold, 7J grains, f for tonu*
1 2 Ounce Graduate,

PRIOE OOMPLiETE, $G.OO
Securely packed in a Paper Case.

1 Lb. Hyposulphate of Soda.

2 Dozen sheets 9x11 Card Board, with Gilt
Form.

1 \ Pint Jar Parlor Paste.

1 1| inch Bristle Brush.

1 Glass Form (for trimming prints.)

1 Robinson's Straight Trimmer.

FOR SALE BY

R. & J. BECK,

1016 CHESTNUT STREET,

PHILADELPHIA, PA.

(OVER)

ti

TO MEET WITH SUCCESS

Ferrous Oxalate Developer

w

I KEYSTONE GELATINE DRY PLATES, *

a — * — $

<J Provide two bottles and in them mix the following solutions: H

P

M»H

Hyposulphite of Soda, 3 ounces.
Water, 20 "

After fixing, wash the plate in clean water, then immerse for five
minutes in a saturated solution of Alum, wash in one or two changes of
water and set up to dry, then varnish, after which the negatives are ready
for the frame in which the printing is done.

J3 ( Bromide of Potassium 20 grains.

}4 Solution I. < Neutral Oxalate of Potash, 5 ounces.

M (Water, 20 " |"

I* ( Sulphuric Acid, 20 drops. Vj

W Solution 2. < Protosulphate of Iron, 5 ounces. *M

<J (Water, 20 " t*

o

pj A large supply of these may be made, as it keeps good for a long |_j

ft time. Shortly before developing a negative, mix together the above in T^

^ the following proportions: -.

f* SOLUTION 1, 4 OUNCES.

O 2, \ OUNCE.

M

" Pour into a flat dish and immerse the exposed plate, the image upon (Jl

rl which will rapidly appear and continue to acquire density. O

u If Solution No. 1, does not turn Blue Litmus paper slightly red, then JjJ

Wadd to it a few drops of Oxalic Acid Solution until it does, JJ

H-
O

0

ro

wi^twm bavr- ©

n

<1 When the image is fully developed, wash with water and immerse in

M the following until the milky appearance entirely disappears. If however, 6

rtit be inconvenient to use it in a bath, the Solution may be poured upon ^

the plate from a bottle. 7*

O

THE

SCOVILL

Portable

Dry Plate Outfits

FOR AMATEURS.

Old Style Equipment. New Style Equipment.

The increasing interest in Dry Plate Photography, and the impetus
given by it to the work of the amateur, has created a demand for a special
apparatus which is light, compact, and easily carried about. We are, as
usual, up to the requirements of the times. The Cameras and Apparatus
of our make are known to be in every respect the most accurate and of the
lightest weight of any in the world.

We beg to call your attention to the following Price Lists of

NE PLUS ULTRA APPARATUS OUTFITS,

M Articles of wMch are Warranted Accurate in every Respect,

OUTFIT A, complete, price $10 00, comprises

A View Camera (black) with rubber bellows and rigid platform, for
making 4x5 inch pictures.

1 Patent Patent Double Dry Plate Holder.

1 Tripod Camera Stand.

1 " Waterbury" Achromatic Nickel Plated Lens with Standard English
Flange.

1 Carrying Case.

OUTFIT B, complete, price $12 00, comprises

A View Camera for taking 5x8 inch pictures. Same style as A Camera.

1 Patent Double Dry Plate Holder.

1 Tripod Camera Stand.

1 "Waterbury" Achromatic Nickel Plated Lens with Standard English
Flange.

1 Carrying Case.

OUTFIT C, complete, price $18 50, comprises

A View Camera (black) for making 5x8 inch pictures.

This Camera is constructed so as to make either a. Cabinet Picture on
the full size of the plate (5 x 8 inches), or by substituting the extra front
(supplied with the outfit) and using the pair of lenses of shorter focus, it
is admirably adapted for taking stereoscopic negatives, also by the same ar-
rangement two small pictures, 4x5 inches each, of dissimilar objects can
be made on the one plate. Included in this outfit are also —

1 Patent Double Dry Plate Holder.

1 Large "Waterbury" Achromatic Nickel Plated Lens with Standard
English Flange.

1 Pair "Waterbury" Achromatic Nickel Plated Matched Stereoscopic
LenSes.

1 Tripod Camera Stand

1 Carrying Case.

American Optical Company's
Apparatus Outfits.

This apparatus is manufactured in New York City under our imme-
diate personal supervision ; and, as we employ only highly skilled work-
£ men, and use nothing but the choicest selected materials, we do not hesi-
b/D tate to assert that the products of our factory are unequaled in durability,
*3 excellence of workmanship, and style of finish. This fact is now freely ^
conceded not only in this country but throughout Great Britain, France, 2
+s Germany, Australia, and South America.

^ Quality being considered, our prices are moderate, as the same grade p

f* of apparatus cannot be supplied for less price.

9 OUTFIT No. 201, complete, price $26 50, |

& CONSISTS OF h.

A Mahogany Polished Camera for taking pictures 4x4 inches, with O
t» Folding Bellows Body, single swing, hinged bed, and brass guides. It has

q* a shifting front for adjusting the sky and foreground, also — h*

■g 1 Patent Double Dry Plate Holder. _

§ 1 Taylor Folding Tripod. <?

1 Canvas Case to contain Camera and Holder. H

$ OUTFIT No. 202, complete, price $27 OO, %

£ CONSISTS OF pj

^ A Folding Mahogany Camera for taking 4x5 pictures, same style as ^
© 201 Camera, also — g"

"** 1 Patent Double Dry Plate Holder. g*

9

I— <

3

1 Canvas Carrying Case. *g

1 Taylor Folding Tripod.

<?*

g OUTFIT No. 203, complete, price $41 00, t

0 CONSISTS OF ^

* A Folding Mahogany Camera, fully described in the American Optical P

_ Company's Catalogue, and well known as the 76 Camera (see illustration.) 9

It is adapted for taking 5x8 pictures, and also for stereoscopic views — M
u together with

O 1 Patent Double Dry Plate Holder. >3

" 1 Canvas Carrying Case. P

1 Taylor Folding Tripod. <?

Cameras in Outfits 202 and 203 have shifting fronts, and are equal in *
style and finish to the best of the American Optical Company's make.

Our New PATENTED Double Dry Plate Holders are the best made,

and answer the demand in dry plate work for something that will exclude
all light. Prices of Extra Patent double Dry Plate Holders are as follows :

4x4 Holders for two Plates each,$3 00

4x5 " " " " 3 00

5x8 " " " " 4 00

MORRISON'S

Wide - Angle View Lenses. %

PATENTED MAY 21, 1872. ^

P -*<m*m^ a

W
O
D
P

W These Lenses are absolutely rectilinear ; they embrace an angle of %

^ fully 100 degrees, and are the most rapid wide-angle lenses made. We rec- d

ommend them for use with the foregoing outfits. j

W PRICE OF MORRISON'S WIDE-ANGLE LENSES. £

W Price. W

2 No. 1, f diam. of lens, 4 x 4 in. plates, 3 in. equiv. focus, each, $25 00 j£

W No. 2, 1 " " 4 x5 " 3| " " " 25 00 ra

•J No. 3, 1 " " 4ix7i " 4± " "" " 25 00 r

No. 4, 1 " " 5x8" 5± " " " 25 00 W

d 0 z

§ Morrison9 s Rapid Stereoscopic Lenses $

& FOR INSTANTANEOUS VIEWS OR LAWN GROUPS 2

W

£h Are entirely different in many particulars from any other lenses in the p0

(0 market. They are 6 inches focus and 1£ inch in diameter, and of course *r\

W can be obtained in matched pairs, if desired. By using a set of diaphragms W

PP provided they are adapted for making 5x8 views. O

A novel and ingenious instantaneous drop is also provided, passing H

W through the brasswork, on the same principle as a central stop, by which t~j

E absolutely instantaneous views, 4x5 inches, may be made, sharp all over to ^

H the very edges, without being diaphragmed down. J>

>« PRICE each, $40 00 j~!

P * *°

B "Peerless" Quick Acting Stereoscopic Leases, g

tn FOR PORTRAITURE OR VIEWS. ^

o O

pr We can also furnish the following, either single or in pairs : _

|~J The Lenses are especially designed for Stereoscopic Photography, and £~J

*• are so constructed that they will work well for interiors or exteriors. 3*

M They are particularly adapted for instantaneous work. W

Diameter of Lenses, 1^ inch ; focal length, 3h inches. «

By removing the back lens and substituting the front combination, a

focal length of 5-£ inches is obtained. C

They are supplied with six Waterhouse diaphragms in morocco case. W

Price, per pair $25 00 W

Imitation Dallmeyer Lenses for Landscapes. Price, per pair $17 00

(0

4)

o

O

m

>
O

O

C

£

3

CO

III
cc

D

o

XL

<

E

O

h-

5

o

x

s

-LITRE U

COVILL'S X TJEE VHEMICALS
AND ACCESSORIES,

■g FOR n^E-A-KIIlsrO NEGATIVES.

We offer with either N. P. U. Outfit " A," or A. 0. Co. Outfits
201 and 202, the following goods packed securely in a wooden
case : —

4x5 Japanned Pans,

4 oz. Graduate,

set 5 in. jap. Scales and Weights.

oz. Bromide Ammonium,

lb. Neutral Oxalate Potash,

" Proto Sulphate Iron,

" Hypo Sulphate Soda,

1 lb. Alum,

1 oz. Sulphuric Acid,

1 bottle Keystone Varnish,

1 doz. 4x5 " Dry Plates,

1 Scovill Note Book,

1 " Focusing Cloth,

1 W. I. A. Ruby Lantern.

PRICE, COMPLETE, $6.50.

With N. P.U. Outfits " B" and "C," and A.O.Co. Outfit 203,we
supply the same goods with the exception of the substitution of
5x8 Pans and Plates for the 4x5 size.

PRICE, COMPLETE, $7.50.

Be sure that your chemicals are marked

S. P. C.

If they are thus labelled, success is guaranteed.

73

CD

o

S

-4
O

2
>

m

O

H
C
73
m

CO

O

o

3-

o

o

<

<D

^1

O

CD

3

Ready Sensitized Paper, .
Scovill's Focusing Glasses,

per dozen sheets, $3 00 w

each,

75

COMPLETE EQUIPMENTS PROMPTLY FURNISHED.

. cfe tf". :B3ESOX3L,

1016 CHESTNUT STREET,

PHILADELPHIA, PA.

PRICE LIST

OF

Walker's Pocket Camera

WITH COMPLETE

PHOTOGRAPHIC OUTFIT,

One seldom gazes upon the beauties of nature or art without

at least a desire to perpetuate in more substantial form than

mere memory the thing of beauty, and that photography offers

greater facilities for a rapid and accurate record than any

pother process, few will question.

HSH The discovery of Daguerre startled the entire scientific
pp world. But the process began and ended with one image upon
one plate without hope of reproduction except by photograph-
ing the original plate.

Then came the "Negative" a permanent semi-transparent reversed picture
on glass. It is obvious if paper sensitive to light be placed under a negative
and exposed to light, such paper will undergo a chemical change in direct pro-
portion as the negative shields from or exposes it to the light, and thus an
indefinite number of prints, or as they are commonly known photographs, are
produced.

The old, or as is commonly known the "Wet" process of producing a nega-
tive involves tedious and dangerous methods which but few amateurs have zeal
enough to master and fewer still the patience to follow. But a great change has
come and while the negative is still the medium of reproduction, the amateur
has the last obstacle removed to the successful practice of photography by the
use of the new Dry Plates.

When Walker's Pocket Cameras were first placed upon the market, the
over-wise scouted the idea of the Art of Photography being mastered by am-
ateurs from any printed instructions; such belief being based undoubtedly upon
their knowledge of the various text books upon the subject, which, though plain
enough to the professional, were worse than Greek to the uninitiated.

Walker's Pocket Cameras are designed especially for amateurs, and are
the outgrowth of a demand for light, compact and accurate apparatus ; the pho-
tograph taken being 2f x 3£ inches, and the entire Field Outfit weighing but
two pounds. The Complete Outfit consists of Camera, Tripod, Double Dry
Plate Holder, Dark Box, Ruby Lamp, 1 Dozen Dry Plates, Printing Frame,
Sensitized Paper, and other articles enumerated on following page. A carefully
prepared Instruction Book, free from technicalities and ambiguities, is also
furnished with each outfit, and so simplifies the art of Photography, that it is
readily acquired by any one without previous experience.

The so called " Outfit" heretofore offered consists simply of a Camera, Tripod
and Plate Holder, a totally inadequate aid to the would be photographer, who
really needs everything necessary for the production of a finished photograph,
including complete instructions, or he is as helpless with his " Outfit" as a ship
without a helm.

The year 1882 opens with a large number of instruments in the hands of am-
ateurs who, with very few exceptions, were totally ignorant of apparatus or

processes, previous to purchase. Exchange Clubs have been formed and a gen-
erous rivalry to excel in excellence has resulted in a development of skill and
artistic taste beyond the fondest hopes of the most sanguine. What the future
of the art will be none are so bold as to predict, but that it possesses rare powers
of stimulating observation, and will mould the latent taste for the true and the
beautiful into something tangible and permanent, none will question.

1 COMPLETE PHOTOGRAPHIC OUTFIT

Consists of the following necessary articles, and with them any person following
the instructions can easily master the art of photography in a short time. The
Chemicals supplied are sufficient for developing 100 negatives and finishing,
with an additional supply of Sensitive Paper, 500 to 1000 photographs :

*Camera, complete, with Achromatic Lens, nickel plated mount, 2 Diaphragms,
ground focusing glass in frame, Walker's Patent Tripod Head, and Walker's

Patent Hard Rubber Double Dry Plate Holder $10 00

Light-Tight Box, for storing 24 plates or negatives 35

*Ruby Lamp, for use in developing negatives 50

2 Developing Trays, at 25 cents each 50

Graduated Glass 25

2 Camel's Hair Brushes, at 10 cents each 20

*Oxalate of Potash, in £ lb. boxes 20

*Hypo-Sulphite of Soda, in -£• lb. boxes 15

*Proto-Sulphate of Iron, " ± " " 15

*Bottle of Intensifier, 2 oz. , 25

*Gelatine Bromide Dry Plates, package of 1 doz., 65

Printing Frame 60

*Bottle of Negative Varnish, 2 oz., 50

*Bottle of Permanent Gold Toning Bath, 2 oz., sufficient for toning from

500 to 1000 Pocket Camera prints 1 00

Package 50 Sheets Permanent Sensitized Paper 50

Package 50 Card Mounts, size 4x5 inches, assorted colors, with choco-
late border line 50

Book of Instructions 1 00

The above Complete Outfit sold for $16.00. $17 30

Boxed and delivered at Express office here without extra charge.

The Camera in above outfit is supplied in either of three styles, Mahogony
finish, Ebonized or Cherry, as desired, at same price. The Dry Plates, also
are of two varieties known as Rapid and Instantaneous, the Rapid requiring in
an average light about three seconds exposure, the Instantaneous, about one-half
that time, fully explained in Instruction Book. The Dry Plates, Sensitive Pa-
per, and Card Mounts, are put up in packages as above and cannot be sold in
less quantities.

PRICE LIST OF ACCESSORIES.

In addition to the above necessities to a photographic outfit, some persons de-
sire a few of the conveniences or luxuries in the way of accessories, we therefore
quote the following :

Walker's Patent Hard Rubber Double Dry Plate Holders, each .$ 3 00

Leather Pouches and Shoulder Strap, for carrying- Camera on hip, with

nickel name plate, clasp, and attachment for tripod legs 4 00

Water-proof gossamer, focusing cloth 1 00

Velvet " " 100

Album Case, representing a closed book, for Pocket Camera Photographs,

an ornament to any library table $J 50

Absorbent Cotton, for filtering, per box 25

Camel's Hair Brushes, 1 inch wide, each 30

PRICE LIST OF PARTS.

Walker's Pocket Camera is made on a system of interchangable parts, in case
therefore of accident any breakage can be readily replaced at a trifling expense :

Camera Boxes, corrugated, and blackened, with frame and focusing glass,

complete $3 00

Lenses, with nickel plated mount, complete 3 00

' ' without mount 2 00

Ground Focusing Glass, cut to Pocket Camera size 25

*Tripod Legs, each 75

" Heads and Sockets, complete 75

Hoods, or Lens Tube Caps, each 25

Diaphragms, two sized openings 25

Light Excluding Shutter, for Plate Holder, each 25

Clasps, for Plate Holder, each 25

All articles enumerated in above lists, except those marked thus * can be sent
by mail to any part of the IT. S. or Canada; those marked, must positively be
shipped by express. In ordering goods to be forwarded by mail, add 5 cents
extra to price of each article for pre-payment of postage, and 10 cents addition-
al for each package if same is to be registered.

THE HMSTEUR PHOTOGRAPHER,

A complete and comprehensive essay on Modern Photography, explaining the
greatest improvement of later years in the art, known as the Gelatine Dry Plate
Process, and beautifully illustrated with sample photograph produced with
Walker's Pocket Camera in the hands of amateurs totally ignorant of the art of
photography. Price, 10 cents.

TERMS OF SALE.

Our terms are inveriably Net Cash by draft on New York, Registered Letter,
or P. 0. Order made payable to us. Checks of parties unknown to us not accept-
ed unless certified, all checks must include 25 cents to cover exchange.

C. O. D. orders, with privilege of inspection, will always be honored when
accompanied by one-half the value of the goods ordered. The return charges
to be paid by the person ordering the goods.

SHIPMENTS.

All goods are carefully packed, marked in exact accordance with instructions
and delivered at Express office here withoui charge.

We will not be responsible for breakage, accident or delaj after the goods
leave our possession.

TESTIMONIALS.

At the Exhibition of scientific apparatus made before the American Association for the ad-
vancement of Science, and the ninth Cincinnati Industrial Exposition, 1881. The jury reported as
follows: To William H. Walker for "Best Portable Photographic Apparatus for field use."

The jury concur in making the award of the silver medal for the intrinsic merit and superior
excellencies in the following particulars, viz : Economy, Portability, Convenience, Corrugated
lining, Tripod Head.

[Signed] H. B. Furness, )

G. M. Allen, \jury.
F. W. Langdon, )

UNIVERSITY OF ROCHESTER— CHEMICAL LA BRA TORY.

Rochester, N. Y., Nov. 15, 1881.
Walker's Pocket Camera and its accessories constitute a marvel af mechanical ingenuity. It
reduces a whole photographic outfit to the very minimum of bulk. Every part down to the most
hidden detail, shows the highest skill of contrivance and the most thorough workmanship.

It so happily overcomes the difficulties of manipultion that any careful person, who will faithful-
ly follow the directions, although without previous experience, maybe satisfactorily successful from
the very start. S. A. LATTIMORE.

ROCHESTER ACADEMY OF SCIENCE.

Rochester, N. Y., Nov. 30, 1881.
Walker's Pocket Camera is a marvel of compactness and excellent workmanship, and does its
work in a surprisingly beautiful and perfect way. I have used it under all sorts of difficulties, and
the more I use it the better I like it. It is invaluable to any one who wishes to preserve fine land-
scapes, and may be adapted to a variety of other uses as occasion requires. In brief, it is perfectly
satisfactory. MYRON ADAMS.

Delaware, Ohio, Oct. 7, 1881.

On the whole, your little Photographic outfit is very cheap, accurate and reliable. With its

help I have learned the art of Photography, and this is fully worth fifteen dollars.

With a larger instrument the cost of this lesson would have been double. I shall always speak

a good word for your outfit to any who may wish to learn the art.

H. W. JONES.

R. & J. BECK,

^MANUFACTURING t OPTICIANS,^

1016 Chestnut Street, PHILADELPHIA.
1GENTS FOR " WALKER'S POCKET CAMERAS,"

AND ALL AMATEUR PHOTOGRAPHIC SUPPLIES.
CATALOGUES FREE TO ANY ADDRESS.

Books on the Microscope

AND OTHER

SCIENTIFIC INSTRUMENTS.

Any work in the following list, will be mailed free to any address in the
United States or Canada, or receipt of the price.

1000. Nugent. A Treatise on Optics. By E. Nugent. Profusely illus-

trated, $2 00

1001. Dick. The Telescope and Microscope. By Rev. Thomas Dick.

192 pages, 50

1002. "Wood. Common Objects of the Microscope. With 400 illustra-

tions, printed in colors, 50

1003. Cooke. 1000 Objects for the Microscope. With 400 illustrations.

By M. C. Cooke, . 50

1004. Cooke. Microscopic Fungi : An Introduction to the Study of

Rust, Smut, Mildew and Mould. Illustrated by nearly 300
figures, colored. By M. C. Cooke, author of British Fungi, etc., 2 50

1005. Hogg. The Microscope : Its History, Construction and Applica-

tion. Being a familiar Introduction to the Use of the Instrument
and the Study of Microscopical Science, with Directions for Col-
lecting, Preserving and Mounting Objects. Illustrated with
upwards of 500 engravings and colored illustrations. 750 pages, 3 50

1006. Beale. How to Work with the Microscope. By Lionel S. Beale,

M.D., F.R.S. Fourth edition, greatly enlarged, . . . . 7 50

1007. Beale. The Microscope, and its Application to Clinical Medicine.

By Lionel S. Beale, M.D., F.R.S. Fifth edition, 1880, . . . 7 50

1008. The Aneroid Barometer. Its Construction and Use. Compiled

from several sources, and reprinted from Van Nostrand's Maga-
zine. 106 pages, f 50

1009. Carpenter. The Microscope and its Revelations. By Dr. W.

B. Carpenter. Latest edition, 25 plates and 449 wood engravings,

848 pages, 5 50

1010. Griffith. Elementary Text-Book of the Microscope, with a

Description of the Methods of Preparing and Mounting Objects,
etc. With 12 colored plates, 451 figures. By J. W. Griffith, M.D.,
F.R.S., 3 00

1011. Davies. Hand-Book on Preparing and Mounting Microscopic

Objects. Latest edition, fully illustrated and brought up to the
present time. By Thomas Davies, 1 25

171

172 E. & J. BECK, PHILADELPHIA.

1012. Lankester. Half hours with the Microscope. A Popular Guide

to the use of that instrument, 130 pages. Profusely illustrated.

By Edwin Lankester, M. D., §1 25

1013. Stowell. The Student's Manual of Histology. A Text-Book for

the Student, and a Complete Guide for the Practitioner and Micro-
scopist. By Prof. Charles H. Stowell, of the University of Michi-
gan. 300 pages, octavo, with 192 engravings, 2 00

1014. Gibbes. Practical Histology and Pathology, 107 pages. New. By

H. Gibbes, London, 1 00

1015. Suffolk. On Microscopical Manipulation. Being the subject-

matter of a Course of Lectures delivered before the Queckett
Microscopical Club. By W. T. Suffolk, F.R.M.S., with 49 en-
gravings and 7 lithographs, 2 00

1016. Gosse. Evenings at the Microscope, 477 pages. Profusely illus-

trated. By Philip Henry Gosse, F.R.S., 1 50

1017. Seiler. A Compendium of Microscopical Technology, for the

use of Students and Physicians. 130 pages and numerous illus-
trations of Apparatus. By Dr. Carl Seiler, Philadelphia, . . 1 00

1018. Martin. A Manual of Microscopic Mounting. Profusely illus-

trated with wood-cuts and drawings on stone. By John H.
Martin, 3 00

1019. Phinn. Practical Hints on the Selection and Use of the Micro-

scope, By John Phinn. 131 pages, illustrated, .... 75

1020. Slack. Marvels of Pond Life. Fourth edition, with colored

plates and numerous wood-cuts, 2 00

•

1021. Smith. How to see with The Microscope. By Prof. J. Edwards

Smith. With profuse illustrations, . . . . 2 00

1022. Beck. A Treatise on the Construction, Proper Use and Capa-

bilities of R. & J. Beck's Achromatic Microscopes. By Richard

Beck. Royal 8vo., with 27 plates, 5 00

1025. Proctor. Half-Hours with the Telescope, with numerous illus-

trations on stone and wood. By Richard A. Proctor, F.R.A.S., . 1 25

1026. Frey. The Microscope and Microscopical Technology. A Text-

Book for Physicians and Students. By Dr. Heinrich Frey, Pro-
fessor of Medicine in Zurich, Switzerland. Translated from
the German and edited by George R. Cutter, M.D., Clinical
Assistant to the New York Eye and Ear Infirmary. Illustrated
by 343 engravings on wood, and containing the price-lists of the
principal Microscope-makers of Europe and America. From the
last German edition. In one handsome 8vo volume, bound in
extra cloth, new edition, 6 00

1027. The Micrographic Dictionary. A guide to the examination

and investigation of the structure and nature of Microscopic
Objects. By J. W. Grffiths and Arthur Henfrey. 845 pages,
illustrated by 48 plates and over 800 wood engravings. Third
edition, London, 1875, 22 00

1028. Wythe. The Microscopist. Last edition greatly enlarged and

profusely illustrated. By Dr. J. H. Wythe, 4 50

INDEX.

PAGE

Absolute alcohol 93

Accessory apparatus for micro-
scopes 18-61

Achromatic Amplifier 18

Achromatic condensers 18, 39, 50, 60

Achromatic marine, field and opera

glasses . 123-131

Achromatic object-glasses for mi-
croscopes 17, 39, 60, 81

Achromatic object-glasses for tele-
scopes 102, 118, 122

Achromatic right-angle prism 18

Achromatic spy-glasses and tele-
scopes ....106-122

Achromatic triplets for the pocket. 67

Adapter for International stand 18

Adapter, for object glasses 38

Adapter on stand 18-38

Adhesive labels 95

Adjusting cone for eyes 154

Air pump 69

Aluminium opera-glasses 130

" field " 131

Amateur's Photographic Camera.... 170
Ametrometer, Dr. Thomson's. ..150, 151

Amici's prism 18

Amplifier, Achromatic 18

Anatomy of the eye 133-135

Animalcule cages 19, 39, 50, 60, 98

Annular micrometer for telescopes, 122

Aplanatic Reading Glasses... 103-106

Artificial Eyes 154

Asphalte 93

Astigmatism 140, 141

Astigmatic diagrams, Dr. Green's, 155

Astronomical telescopes 109-122

Atwood's Hard Rubber Cells 92

Bands of Test Lines, Fasoldt's 101

Bardou's opera-glasses 129

Beck's microscope lamp 19, 99

Beck' s new zoophyte trough 98

Beck's patent illuminator , 18

Beck's Series of Trial Sights 153

Beck's Spring Turn-table 91

Bell-glasses 92

Bell's cement 93

Benzole. 93

Binocular Body, Wenham's 54-55

Black glass polarizer 18

Blue Glass, Light-Moderator 38

Blue-glass slip 19

Books on the microscope 171, 172

Boy's microscope 79

Brass table and lamp 91

Brown's iris diaphragm 18

Brown's rubber cement 93

Brunswick black 93

Bull-nose Forceps 82

Bull's-eye condenser 18

" " with lamp 18

" small 18, 38, 60

PAGE

Bundle of glass polarizer 18

Cabinet, mounting 68,69, 94

Cabinets and cases for microscopes,

14, 38, 59
Cabinets and cases for microscopic

objects 69, 71

Calc spar plates , 18

Camera lucida 19, 39, 50, 60

Camera, Photographic 170

Canada balsam 92

Capillary bottles 94

Capped " 94

Carmine 94

Cases for spectacles 168

Cases of dissecting instruments 84

Cells for micro spectroscope 18

Cells, glass, ebonite, and block tin, 92

Cements for mounting 93

Chains for eye-glasses 168

Circle cutter 93

Clamps for telescopes 108

Claude Lorraine, or landscape mir-
rors 169

Coddington lenses 63, 64, 67, 73

Collecting bottles. 94

Color sense measure 155

Compressors 19, 98

" spring 82

Condenser, bull's-eye 18, 38, 50, 60

Congress Turn-table 91

Conical Diaphragm 38

Cosmorama lenses 102

Cox's Turn-table 91

Crystals for polarizer 18

Cutting forceps 82

Cylindrical glasses 167

Damar, for mounting 92

Dark wells and holders 19, 39, 50, 60

Darker' s series of selenites 18

" selenite stage 18

Deane's medium 93

Demonstration lenses 102

Descripton of Micro Spectroscope.31-34

Diagonal reflector for telescopes 122

Diamonds, glaziers', and writing ... 93

Diaphragm, Conical 38

Diaphragm, Iris 18-38

Diatom Prism, Dr, Woodward's 39

Diatoms 100

Dichroiscope, Sorby's 18

Diplopia 142

Dissecting instruments 82-84

" knives 82

" microscopes, 63, 64, 65, 77, 78

. " needles 82

" scissors 82

Double image micrometer 122

" " prism 18

" nose-piece 19, 39, 60

Draw-tubes ,18, 60

Dr. Thomson's disc 154

173

174

INDEX.

PAGE

Driving-clock for telescopes 122

Dropping and dipping tubes 92

bottles 94

Drying cases... 94

Ec'hinoidea, Type plate of 100

Economic Microscope, The 42-50

Educational objects 39

Elbow scissors 82

Emmetropic eye 137

Engravers' glasses 73

Entomological pins 169

Erecting-glass 18

Equilateral prism 18

Excelsior microscope 78

Eye-glass chains 168

" guards 168

hooks 168

Eye-glasses, frameless 164

gold 161-162

rubber 166

shell 161

" Arundel tinted. 163

" steel 163, 164

Eye, map and diagram of 133, 134

" protectors 160, 161

Eye-piece micrometers 19, 122

Eye-pieces for microscopes, 18, 39,

50, 60

" " telescopes 108, 122

Eye-piece shades 19

" indicators 19

Eye-shades 161

Eyes, Artificial 154

Farrant's medium 93

Far-sightedness 141

Fasoldt's Bands of Test Lines 101

Fiddian's illuminator 19, 99

Field and Marine-glasses... 124, 125, 131

Finders, Maltwood's 19

Flower microscopes 73

Fluids, preservative,for mounting 92-93

Forceps, brass 19, 50, 82

44 bull-nose 82

" cutting 82

" nickel-plated 82

44 paper pointed 19

44 Quekett's 82

stage 19, 38, 50

44 three-pronged 19

Frameless spectacles 160

French object-glasses 81

Freezing Microtomes, - 86-88

Frog plate 19

Gas lamp 19

Gelatine, Seller's Injecting 94

General remarks on spectacles, 132-143

Glass rings for cells 92

44 slips, plain, ground edges,

concave centres..., 92

Glass, thin, sheets, squares and cir-
cles 92
Glass troughs..'. .'.'....,'..'.'." '."'.! 19^ "39, 50, 60

Glass tubes 19

Glasses for spectacles 167

Glaziers' diamonds 93

Glue, Liquid Marine 93

PAGE

Glue, marine 93

Glycerine 92

jelly 93

Gold eye-glasses 161, 162

44 size 93

44 spectacles 155, 156

Goniometer, Leeson's 19

Green's test diagrams 155

Growing cell 19

Guards for eye-glasses 168

Hsematoxylbn staining fluid 94

Hand magnifiers 67, 73-75

Hard Rubber Cells, 92

Hemispherical Lenses ... 39

Histological Dissecting Microscope 65

Holman's current slides 96

44 life slides 95,96

44 parallel compressor 98

44 syphon animalcule cage, 99

44 syphon slide 97

Holmes' Lecture Room Micro-
scope, 62

Holothuridac, Type Plate of 100

44 Horizon Sweep," The 124

Hot Water Drying Case, 94

Household microscopes 80, 81

" objects for microscopes, 101

Huyghenian eye-pieces, 18, 39, 50,

60, 108, 122

Hypermetropia 139

44 Ideal" Microscope, The 35-39

Illuminating apparatus for tele-
scopes 122

Illuminator, Beck's patent 18

Illuminators, parabolic 18

44 white cloud IS

Improved Dissecting Microscope... 63
Improved National Microscope,

The 56-59

Indicators to eye-pieces 19

Injecting syringes 88

44 fluids 94

Insect pins 169

Invisible spectacles 159

Iris diaphragm 18-38

Kaleidoscopes 169

Kellner eye-pieces 18

Key for tightening joints 19

Klaeger insect pins 169

Knives, dissecting 82

44 section 84

Valentin's 84

Labels 95

Lamp with bull's-eye... 18

44 students' 99

44 for microscopes 19, 99

Lecture-room microscope, Holmes' 62

Leeson's goniometer 19

Lemaire's Opera Glasses, 128

Lenses, Coddington 63, 64, 67, 73

44 cosinorama 102

44 demonstration ■ 102

44 hemispherical 39

44 microscope and telescope.. 102

44 reading and picture 103

Lever compressorium 19

INDEX.

175

PAGE

Lieberkuhns 17, 39, 50, 60

Light moderator, Harney's 19-38

Linen provers- 73

Liquid Marine Glue, 93

Lithological Microscope, The 40-41

Live boxes 19,39,50, 60

" traps 19

Magic lanterns 169

Mailing boxes for objects 69

Malt wood's finder 19

Map, or diagram of the eye 134

Marine and field-glasses. ...124, 125, 131

Marine glue 93

Mechanical Stages, 38, 60

Micrometers for microscopes. 19, 39,

50, 60

Micrometers for telescopes 122

Micro-spectroscopes 18

Micro-spectroscopes, Description

of. 31-34

Microscope lamps ...18, 19, 91, 99

44 lenses .... 102

tables 72

Microscope objectives, First-class

series 17

Microscope objectives, National

series 60

Microscope objectives, "Ideal"

series '. 39

Microscope Tables, Revolving 72

Microscopes, Boy's.... 79

44 Economic 42-50

" Excelsior dissecting.. 78

" Improved " 63

" Histological " 65

" New model " 64

School " 77

" Flower 73

Holmes' lecture-room 62

" Household 80, 81

"Ideal" 35-39

4 ' Improved N ational..56-59

International 4, 8

44 Large Best 9-12

44 Lithological 40-41

44 National ..51-55

" Pocket 67,73,75,78

Scholar's 66

Seed 73

Simple 67, 73-78

Small Best 12, 13

Stands 14, 38, 40, 50, 59

The school 76

44 Three legs 73

44 accessories, dissecting

63-64
44 " Economic,42-50

44 " First-class,

18, 30
44 " National, 60-61

44 " " Ideal "...38-39

Microscope Objectives, French 81

Microscope specimen cabinets and

cases 69-71

Microtome, Rivet's, 88

44 Ranvier's 84

PAGE

Microtome, Rutherford's 88

44 Taylor's 87

44 Walmsley's 86

44 Army Medical Museum 84

Millers' spectacles 160

Mineral holder for stage 19

Mirrors, Claude Lorraine 169

44 cylindrical 169

44 magnifying 169

44 multiplying 169

44 plane 169

44 spherical 169

Moller's type and test plates 100

Mounting cabinets 68, 69, 94

" stands 91

Muscular affections of the eye 142

Myopia 138

Nachet's prism 18

44 trial lenses 152

National microscopes 51, 61

Near-sightedness 138

Needles, dissecting 82

Neutral-tint glass, camera lucida... 19

New National Microscope, The 51-55

New Model Dissecting Microscope. 64

Nicol's prisms . ., 169

Nose-glasses.. 161-166

Nose-piece, double 19, 39, 60

44 quadruple 19

44 triple 19, 39, 60

Object-glasses for microscopes, 17,

39, 60, 81
44 " telescopes.... 102,

118, 122

Objects, microscopic 100-101

Oculists' prescriptions 147

Oil of cloves 93

Opal glass slip 19

Opaque disc revolver 19

44 illuminator 18

Opera-glasses 124-131

Ophthalmoscopes 148-150

Orthoscopic eye-pieces 18

Osmic acid 94

44 Our Own" Series of Trial Sights 153

Page's wooden forceps 69

Paper pointed forceps 19

Parabolic illuminator 18

44 reflectors 18, 39, 50, 60

Parlor kaleidoscope 169

Parallel compressor 19-98

44 wire micrometer 122

Pearl opera-glasses 129, 130

Pebbles 167

Perfect sight 137

Physicians, instructions for 147

Picture lenses 103

Pipettes 92

Pocket microscopes 67, 73, 78

Polariscopes 18, 39, 50, 60

Popular objects for microscope 101

Porcelain saucers 94

Portable Telescope Clamps, 108

Postal boxes 69

Presbyopia 141, 142

Prescription paper and diagram.... 147

176

INDEX.

PAGE

Preservative fluids 92,93

Prismatic glasses 1G7

Prisms, Amici 18

" double image 18

" equilateral 18

flint glass 103

Nachet's 18

Nicol's 169

" right-angle 18

" Woodward's ... :J,9

Protectors for the eye, wire gauze.. 160

Punches.. 93

Quadruple nose-piece..... 19

Quekett's forceps 82

Rainey's light moderator 19-38

Ranvier's Microtomes 88

Ranvier's necessaire 84

Reading and picture glasses 103

Reflector's, parabolic 18, 39, 50, 60

" side, silver 19

Reversible compressor 19

Revolving microscope tables 72

Right-angle prism 18

Rivet's Microtomes, 88

Rubber cement, Brown's 93

Rutherford's Freezing Microtome 88

School microscopes 76-77

Scholar's Microscope, The 66

Scissors, dissecting 82

Screw live-box 19

Section cutters 84-88

Seed microscopes 73

Seller's section knife and carrier.... 84

Selenites, Darker' s series 18

Selenite-films 18

" stage.., 18

Shadbolt's turn-table 91

Shades to Eye-pieces 19

Shades, Eye 161

Side, silver, reflectors 19

Silver spectacles 157-158

Smith's mounting instrument 69

Snellens'stest types 155

Sorby's binocular spectroscope 18

" dichroiscope 18

" spectroscope eye-piece 18

" standard spectrum scale... 18

Spectacle glasses 167

" cases 168

Spectacles, Arundel tinted 158

" coquille 160

" frameless 160

" gold 155-157

" invisible 159

" millers' and turners'.... 160

" pulpit 159

" silver 157-158

steel 158-160

Spirit lamp 91

Spot lens .' 18

Spring compressors 82

" scissors 82

Spv-glasses, marine, tourists', and

rifle 106-108

Stage forceps 19. 38, 50

" micrometer 19, 39, 50, 60

PAGE

Stage mineral-holder 19

Stages, mechanical 38, 60

Staining fluids 94

Stand, tripod, for telescopes 108, 122

Steel-disc camera lucida 19

" forceps 82

Student's lamp 99

Sun-glasses 122

Sun-shades 122

Syphon Animalcule Cage 98

Syringes for injecting 88

Tables, revolving, for microscopes. 72

Taylor's Freezing Microtome 87

Telescope lenses 102, 118, 122

" binocular 108

Telescopes, astronomical.- 109-122

" Portable 106-108

" Reflecting 116-118

" Refracting.. 111-116, 119-122

Test-lines, Fasoldt's bands of. 101

Test diatoms 100

" tubes , 92

" types 127-146, 155

" The Gem " opera and field-glass.. 126
" The Pearl" opera and field-glass. 126

Thomson's Ametrometer 150-151

Thomson's metal discs 155

Thin glass 92

Three-legged microscopes 73

Three-pronged forceps 19

Tightening key 19

Tourmalines 18

Trial sights 152, 153

" spectacle frames 153-154

Triple nose-piece 19, 39, 60

Triplets, achromatic, for the pocket 67

Tripod stand for telescopes 108, 122

Turn-tables 88-91

Typen plattes, Moller's 100

Valentin's knife 84

Varley's telescope stand 122

Vertical camera lucida 39, 50, 60

Walker's Photographic outfit 170

Walmsley's Double Stainings 101

Walmsley's Freezing Microtome... 86

Walmsley's mounting cabinet 94

Walmsley's turn-table 88

Watchmakers' glasses 73

Watch-glasses 92

Wax cell punch 93

Weber's life slide 19

Wenham's binocular body 54-55

" compressor 19

" parabolic reflectors..l8,

39, 50, 60

White cloud illuminator 18

White zinc cement 93

Wire-gauze eye-protectors 160

Wollaston's camera lucida..l9, 39, 50, 60

Wooden forceps 69, 82

Woodward's Diatom prism 39

Wright's collecting bottle 94

Writing-diamonds 93

Zinc cement 93

Zoetrope, or Wheel of Life 169

Zoophyte trough 19, 39, 50, 60, 98

The present or 1 Ith edition of our American Catalogue completes
the list of Optical Iustruments and Accessories. Its bulk has grown
to such an unexpected extent that we deem it expedient to issue a
Second Part (now in course of preparation), which will contain fully
illustrated descriptions of Thermometers and Barometers of every
description, Compasses, Anemometers or Wind Gauges, Rain Gauges,
Hydrometers, Hygrometers and Urinometers.

The expense attending the issue and postage of these Catalogues is
so great that we shall feel obliged if our friends, in sending for them,
will inclose Fifteen Cents in stamps or currency, which will tend some-
what to defray the cost.

We have issued a Condensed Catalogue of Thirty-Two Pages, which
will be mailed to any address in the world free, on application.

COUNT WAY LIBRARY OF MEDICINE

QH
219
B3?
1582

RARE BOOKS DEPARTMENT