THE VERANT IN USE, ALLMETAL +ADD TO +

MODEL YOUR SUCCESS

graphic objective; and, on the other 00

hand, the lens is free from any deforma8a etime now wasted in adding

tion for a diaphragm distant 27 millilong columns by using

meters (1.06 inches) from the nearest lens THE LOCKE ADDER.

surface, the rotating center of the obIt minimizes time, expense and drudgery of business details. 'Adds, subtracts, multiplies

serving eye having to be placed at that and

divides. Capacity, 999,999,999. 'Cannot make a mistake. One of the fastest adding machines

point. made. No complicated mechanism to get out of

These different conditions will result order; no expert repair man's bills to pay; no breaks cause delay and inconvenience. Ready to use any time,

in a normal eye view instead of the small any place. Simple, light, handy. Size, 4x10% inches. All metal. Price, $5.00, prepaid in U.S. Send

photograph, a distant image of the latBuy

for FREE descriptive booklet. Agents wanted. a Locke

ter being free from any deformation (if C. E, LOCKE MFG. CO., Adder to 32 Walnut Street, Kensett, Iowa.

the eye be placed at the point of no deSave Your Brain.

formation), and fulfilling the same conditions as to apparent size, shadows, and relative distinctness as in the case of the objects being inspected from the objective of the photographic camera. The im

pression thus produced by the small is the largest and the most important number of a photograph will be much more true to power plant paper ever issued. The price of a single copy to non-subscribers, is

nature; and the main consequence will 50 cents. Subscribe now, send us one dollar, and you be an unconscious production of a true will receive the New Year's Number and 23 other numbers during 1905.

image agreeing with the different marks Let us tell you how you can make money by getting new subscribers. One Dollar a Year. Issued

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through the apparatus will therefore proThe Engineer Publishing Company duce quite as plastic effects as in the case 357 Dearborn Street Chicago, Illinois of being regarded with both eyes through

a stereoscope.-DR. A. GRADEN WITZ. Mention The Technical World.

THE

NEW

YEAR'S

NUMBER

OF

The Engineer

HERE'S A FEW OF THE PARTS NAMED-THERE ARE 497 IN ALL. 22-12-inch guns.

278—Refrigerating room. 23--Sighting hoods-11-inch armor.

291-Crew's hammocks. 41-Conning tower-9-inch armor.

313-Broadside torpedo tubes. 42-Rapid fire guns-1 pounders.

3:20 - Submarine mines, 63-Upper fighting top.

336-12-inch shells. 69A --Code signal-*We can defend ourselves."

344-Upper dynamo room, 70A-Speed cone-"Full speed ahead."

358-Exhaust air from dynamo room. 193-6-inch guns.

362-Coal bunkers.

Mention The Technical World.

Practical Books

CONSULTING
DEPARTMENT

Just Ready-Centrifugal Fans, by J. H. KinealY.

M. Am. Soc. M. E. Dealing with their designing, construction and use with numerous Formulas, Illustra

Dry Battery-Electro-Gilding Bath tions and Tables. Suitable for archi

Question 1: How can I make a pocket dry tectural and engi

battery? neering drawings.

Question 2: How can I make an electro

gilding bath which gives a red color like 14SYSTEM 8 NEW

or 18-carat gold?-. V'. C. ALPHABETS.

Answer 1: Dry cells are sold at such Вү

a low price that it does not pay an indiJ.H.CROMWELL

vidual to spend his time in the manufactNinth Thousand.

ure of a cell. A dry battery may be By Mail 50c.

made in the following manner: Care and Handling of Electric Plants.

A jar of the desired shape is made of With very useful table, formulas and suggestions and 66 original drawings.

zinc; heavy sheet zinc should be used In limp leather Price $1.00

and bent into the required form, then

soldered in such a manner that it forms Spon & Chamberlain a jar. It will be found difficult to solder Publishers TECHNICAL BOOKS

zinc. All parts where it is desired the T. W., Liberty Building,

solder should stick should be carefully NEW YORK

cleaned by scraping, and clean chloride of zinc used as a flux. The zinc should have a brass binding-post soldered to it. The other electrode is usually carbon,

and should have a similar binding-post Twentieth Century

fastened to it.

The contents of such cells vary. In Locomotives

Gassner's cell, the following mixture is

used: ANGUS SINCLAIR COMPANY

Oxide of zinc, i part by weight; sal-ammoniac, 1 part; plaster of paris, 3 parts; chlo

ride of zinc, i part; and water, 2 parts. Newly Published and is the

The cell is sealed by means of covering Best Book on

with pitch, or some similar material Railway Machinery

which will not allow salts to creep. There ever published. Contains

are many other formulæ for the contents chapters on: Elementary

of the cell, which are used with success. lessons on first principles; steam and motive power;

Answer 2: The following solution, workshop operations; loco

recommended for red plating, should be motive boiler construction;

used hot (at the boiling point) with a compound locomotives;

platinum wire for the anode and with valve motion; machine tools and shop appliances, and

high current density: on nine other subjects.

Phosphate of soda (crystallized), 60 parts; PROFUSELY ILLUSTRATED.

bisulphite of soda, 10 parts; cyanide of potasContains 670 pages, 6x9 inches.

sium (C. P.), I or 2 parts; neutral chloride PRICE, THREE DOLLARS

of gold, 2 parts; distilled or rain water, 1,000

parts. LOCOMOTIVE ENGINEERING First dissolve the phosphate of soda in

800 parts of hot water. When thoroughly Department T, 136 Liberty Street

dissolved, filter the solution if not clear, NEW YORK

and allow to cool. Dissolve the gold

chloride in 100 parts water, and the biMention The Technical World.

BY

Compendium of Drawing

A COMPLETE CYCLOPEDIA

For the Library, the Shop, the Student

UVM ING

900 Pages-1,000 Illustrations, Folding Plates, Etc.

SENT

FREE

FOR EXAMINATION

REGULAR price, $10.00, reduced nearly

one-half in order to introduce the Size 8 x 10

work. No more comprehensive treatise on inches

drawing ever published. $25.00 would not

buy separate volumes covering the subjects. Practical test questions combine the advantages of a text-book with a Cyclopedia of Drawing.

OSWALD GUETH, M. E., Consulting Engineer, Technical Editor of "Cold Storage
and Ice Trade Journal," New York, says:—"'I consider the 'Compendium of Drawing'
very thorough and complete for home study, and of excellent value for reference."

INTRODUCTORY OFFER

NOT GOOD AFTER FEBRUARY 28th

BOTH VOLUMES sent free on approval (express prepaid). Keep them five days. If satisfactory send $1.00 and $1.00 per month for five months thereafter. Otherwise notify us and we will transfer them absolutely free. They have a permanent utility that makes them a desirable acquisition to every library.

LIST OF AUTHORS AND SUBJECTS

Part I PROF. E. KENISON, M. I. T.

Mechanical Drawing PROF. H. W. GARDNER, M. I.T.

Shades and Shadows PROF. D. A. GREGG, M. I. T.

Rendering in Pen and Ink PROF. W. H. LAWRENCE, M. I. T.

Perspective Drawing
FRANK CHOUTEAU BROWN, Arch., Boston

Arch. Lettering
Part II
PROF. W. H. JAMES, M. I. T.

Working Drawing

Mechanism PROF. C. L. GRIFFIN, formerly Pa. State College Machine Design WM. NEUBECKER, N. Y. Trade School, Sheet Metal Pattern Drafting

Tinsmithing

.....CUT OFF HERE.. American School of Correspondence, Chicago:

Please send me free, on approval (express prepaid), one Compendium of Drawing, as advertised in The Technical

AMERICAN SCHOOL OF CORRESPONDENCE

CHICAGO, ILL., U. S. A.

St. and No..............................

State

City

World, February.

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3 Months Free

Months Free Sary thickness of the tube can be de

Mention Tlie Technical World,