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pieces being the softest possible cast iron. The magnets and the pole-pieces form a solid frame, being held together by nuts on the tapped ends of the magnets. The armature, which is of the Gramme type, is supported by brackets of brass bolted to the polepieces, and the shaft runs in phosphor-bronze bearings fitted to the brackets. The armature is made of annealed wrought-iron wire supported by a three-armed spider of brass.
The brush arrangement is of improved construction, original with the designer, and enables the tension of the brushes to be ad justed without disturbing the setting of the same, and without exposing the attendant to shocks from the machine. This is effected by an insulated thumb-screw, – aside from the thumb-screw that holds the brushes, — which clamps the brush-holders to the brushpin. The rocker-arm is also movable. The cables from the brushes are carried to a board on top of the machine, on which are
two horse-power, and, being very compact, occupies a floor-space of only ten by nineteen inches, with a height of twelve inches.
The armature is of the Gramme ring type, and the pulley end of the shaft has its bearing in the neutral part of the field-magnet. The shaft is of English tool steel of the best quality, the bearings are ground true on dead centres, and the armature is so attached as to practically constitute a portion of it, avoiding all danger of loosening, — a point of importance in this class of machinery. Ball bearings are used, adınitting of self-alignment. They are made of phosphor-bronze, hand-reamed, and of considerable length, to give an even bearing surface and prevent all tendency to heat. The commutator sections are of drop-forged copper, hard, and of almost pure metal. The commutator is attached to the armature in a novel manner, and can be renewed without disturbing the armature wires.
placed the terminals; also a switch for short-circuiting the field. coils, in case it is desired to “paralyze" the machine while running. Thus the switch and terminals are always in sight, and can be attended to at once, if necessary.
A remarkable feature of this dynamo is that it requires exceed. ingly small floor-space for its capacity, — a feature of great value when the space is limited, as on board of ships, etc. The floorspace required for a twelve-light dynamo is only twenty-four by twenty-four inches.
A New Constant-Current Electric Motor. The electric motor shown in the accompanying illustration is one of a series manufactured and placed on the market by the Electric Engine Company of Cincinnati. It is intended to run on a constant-current or arc-light circuit, has a maximum capacity of
The armature is accurately adjusted to a running balance, and provided with means for forced ventilation. The ordinary rockerarm supporting the brush-holder has been dispensed with, thus rendering the important parts more readily accessible.
The governor, the construction of which is shown in the figure, maintains the speed constant under all variations of load from zero to the full designed load of the machine, and is remarkably simple, having but one wearing point. It regulates solely by variation of pressure, practically eliminating motion and wear: hence it has great durability and sensitiveness.
For constant potential circuits, this company manufactures motors of similar design, but differing in detail. As they regulate automatically, they do not require governors. These are made for standard potentials of 110, 220, and 550 volts, though they may be made for any specified voltage.
174 p. [Free of charge to all, if of satisfactory character.
12o. 55 cents.
SARGENT, C. S. Scientific papers of Asa Gray. Vol I. Address N. D. C. Hodges, 47 Lafayette Place, New
Reviews of Works on Botany and Related Subjects, York.) Allsop, F. C. Practical Electric Be!l Fitting. London
1834–87. Vol. II. Essays ; Biographical Sketches, and New York, E. & F. N. Spon. 142 p. 12o. $1.25 Will exchange “Princeton Review" for 1883, Hugh
1841-86. Boston and New York, Houghton, Mifflin, BALLOU, M. M. The New Eldorado : A Summer JourMiller's works on geology and other scientific works, for
& Co. 900 p. 8 . $6.
ney to Alaska. Boston, Houghton, Mifflin, & Co. | STEPHENS, Č. Ar Living Matter : Its Cycle of Growth back numbers of “The Auk," "American Naturalist,"
352 p. 12o. $1.50. or other scientific periodicals or books. Write. – J. M. Be
and Decline in Animal Organisms. Norway Lake, BERNTHSEN, A. A Text-Book of Organic Chemistry. Keck, Chardon, Ohio.
Me., The Laboratory Co. 107 p. 12o.
Tr. by George M'Gowan, Ph.D. New York, Van Tilden, w. s. Common School Song-Reader. Boston, A collection of fifty unclassified shells for the best offer Nostrand. 544 p. 12o.
Ginn. 176 p. 12o. 45 cents. in bird skins; also skins of California birds for those of BLAVATSKY, H. P.' The Key to Theosophy. London,
Theosoph. Publ. Co.; New York, W. Q. Judge. 307
Woman's Cycle, The. Vol. I. No. 1. New York, Mrs. bırds of other localities. Address Th. E. Slevin, 2413 |
C. J. Háley. 20 p. 4°$2.50 per year. Sacramento St., San Francisco; Cal.
p. 12° I have forty varieties of birds' eggs, side blown, first Burt. Mary E. Literary Landmarks. Boston and New class, in sets, with full data, which I will exchange for
York, Houghton, Mifflin, & Co. 152 p. 16o, 75 books, scientific journals, shells, and curios. Write me,
cents. stating what you have to offer. - Dr. W. S. STRODE,
CHAMBERS, G. F. A Handbook of Descriptive and
Practical Astronomy. I. The Sun, Planets, and Bernadotte, Fulton County, Ill.
Comets. 4th ed. Oxford, Clarendon Pr. 676 p. "I wish to exchange Lepidoptera with parties in the
8o. (New York, Macmillan, $5.25.) eastern and southern states. I will send western species
Cook Book, Presbyterian Compiled by the ladies of the mar8-112 for those found in other localities." - P. C. Truman,
First Presbyterian Church, Dayton, 0. Dayton,
$2. I want to correspond and exchange with a collector of ENSEÑANZA Primaria, Boletin de. Vol. I. No. 1. Monbeetles in Texas or Florida. - Wm. D. Richardson,
tevideo, Dornaleche y Reyes. 80 p. 8o. P.O. Box 223, Fredericksburg, Virginia.
A GAIN OF A POUND A DAY IN THE
CASE OF A MAN WHO HAS BECOME ALL 100 botanical specimens and analyses for exchange. HOUSTON, E. J. A Dictionary of Electrical Words, RUN DOWN,” AND HAS BEGUN TO TAKE Send list of those desired and those which can be fur
Terms and Phrases. New York, W. J. Johnston Co. nished, and receive a similar list in return, Also cabinet
THAT REMARKABLE FLESH PRODUCER, 640 p. 16o. $2.50. specimens and curiosities for the same. Scientific corre- | Kapp, G. Alternate-Current Machinery. (Van Nostrand svoudence solicited. - Ę. E. Bogue, Orwell, Ashta. Science Series, No. 96.) New York, Van Nostrand. County, O.
199 p. 249. 50 cents. to chanters or individual members of the KLEMM. L. R. European Schools: or. What I saw in Agassiz Association, 25 fine specimens of fossil plants the Schools of Germany, France, Austria, and Switfrom the Dakota group (cretaceous), correctly named, for zerland New York, Appleton. 419 p. 12o. $2. $2.50. Send post office order to Charles H. Sternberg LANCASTER, A. Notes Biographiques sur J. (author "Young Fossil-Hunters "), 1033 Kentucky Street, Lawrence, Kan.
LESLEY, J. P. A Dictionary of the Fossils of Pennsyl
vania and Neighboring States named in the Reports One mounted single achromatic photographic lens for
and Catalogues of the (Pennsylvania Geological] Surmaking 4 X 5 pictures, in excellent condition: also one "new model ✔ double dry-plate holder (4" X 5'), for fine
vey. Harrisburg, Geol. Surv. 437 p. 8°. geological or mineralogical specimens, properly classi
Mills, W. A Text-Book of Animal Physiology. New OF PURE COD LIVER OIL WITH
York, Appleton 700 p. 8°. fied. - Charles E. Frick, 1019 West Lehigh Avenue, Morte Philadelphia, Penn.
le, Mott, H. A. A Chart Relative to the Composition. Di Hypophosphites of Lime & Soda
gestibility, and Nutritive Value of Food. ' New York, The undersigned wishes to make arrangements for the
IS NOTHING UNUSUAL. THIS FEAT Wiley. 1°. $1.25. exchange of Lepidoptera of eastern Pennsylvania for MURDOCK, H. The Reconstruction of Europe. Boston
HAS BEEN PERFORMED OVER AND OVER those from other localities. All my specimens are named
and New York, Houghton, Mifflin, & Co. 421 p.
AGAIN. PALATABLE AS MILK. EN. and in good condition. - Charles S. Westcott, 613 North
DORSED BY PHYSICIANS. SOLD BY ALL 17th Street, Philadelphia, Penn.
Nichols, W. F. Topics in Geography. Boston, Heath. DRUGGISTS. AVOID SUBSTITUTIONS AND California onyx. for minerals and coins not in my col 174 P 12°, 55 cents. lection. - W.C. Thompson, 612 East 141st Street, New PARKES, L. C. Hygiene and Public Health. Philadel IMITATIONS. York, N.Y.
| phia, B1.kiston. 47 p. 12. $2.50.
GUARANTY INVESTMENT COMPANY
7° Guaranteed Farm Mortgages 7%
The Company sends each year to Kansas and Nebraska for the purpose of examining its loans and methods of business a
COMMITTEE OF INVESTORS. The Committee for 1889 visited Fifty counties in the two States, examined over 100 farms on which loans had been made and reported every one to be SAFE.
The Company will be glad to send to any address the Report of the Committee which presents a very interesting statement of the general development of Kansas and Nebraska.
A large number of loans equally as good as any examined by the Committee are always on hand for sale.
Address for Monthly Bulletin and Investors' Committee Report
HENRY A. RILEY, General Eastern Manager, 191 Broadway, N.Y. DAFT ELECTRIC LIGHT COMPANY. Power Stations.
Car Motors 15 to "'to 100 H.P.
250 H.P. : Executive Office, 115 Broadway, N.Y.
FACTORY, JERSEY CITY, N. J. Please Mention Science."
ican Bell Telephone COMPANY
CALENDAR OF SOCIETIES.
the pneumatic tubes, and a brief discussion Philosophical Society, Washington.
of governmentally owned telegraphs ; elecOct. 12. – Everett Hayden, Hurricanes intric lighting as carried on in England; the
10% DISCOUNT. the Bay of North America ; Frank Baker, practice of telephony in Great Britain, certain We will allow the above discount to any Work of the Life-Saving Crews during the peculiarities in apparatus and methods ; also subscriber to Science who will send us an
order for periodicals exceeding $10, count. Recent Hurricane : Romyn Hitchcock, The the use of electric motors. Some of the elec ing each at its full price. Action of Light on Silver Chloride. trical features of the Paris Exposition were
Gelatine " cussion of a new tractor recently invented
American Garden ...... by H. L. Van Zile, an engineer of Albany,
American Journal of Philology ..... New York. The invention had resulted
American Machinist ....
American Naturalist... from certain mathematical investigations, AMP
Atlantic... and rendered it possible to make the total
Babyhood..... power, or pulling force, available for traction.
Bradstreet's......... A model had been made, which easily
Building (weekly)...... mounted a 20-per-cent grade, while the same
Carpentry and Building....
Century Magazine. model without the improvement could as
Chautauquan, The ...
Christian Union, The.. cend only a 10-per-cent grade. In the dis
Cosmopolitan, The...... cussion, Robert Moore called attention to the
Eclectic Magazine..... similarity of this device to the Fell tractor,
Edinburgh Review ..... which was in successful use on the Summit
This Company owns the Letters Electrician and Electrical Engineer.... Railway, over Mount Cenis. Professor Gale Patent granted to Alexander Gra
Engineering and Mining Journal... spoke of the probable advantages this motor ham Bell, March 7th, 1876, No. English Illustrated Magazine.... would have for street-railway work, where 174,465, and January 30, 1877, Forest ares
Forest and Stream..........
Forum, The........... the grades were serious, and where objec-No. 186,787.
Garden and Forest.... tions existed to the use of other forms of The Transmission of Speech by Harper's Bazar.:
Harper's Magazine.. tractors. Mr. C. H. Sharman then read a all known forms of ELECTRIC | Harper's we
Harper's Weekly............ paper on “ Some Reminiscences Connected SPEAKING TELEPHONES in- ! Harper's Young People .
| Illustrated London News (Amer. reprin with the Construction of the Union Pacific
| fringes the right secured to this Independent, The........... Railroad." Mr. Sharman entered the engi
ompany by the above patents, and Journal of Philology (Eng.) ...
renders each individual user of tel- Judge... neering department of this road in 1866 as ephones, not furnished by it or its
L'Art.... rod-man, and remained on the work in vari.
licensees, responsible for such un- Lippincott's Magazine..... ous capacities until the completion of the
Littell's Living Age.... | lawful use, and all the conse- ' Litter
London Quarterly ...... road in 1869, when he held the position of
quences thereof and liable to suit Macmillan's Magazine... division engineer. A graphic description
Magazine of American History. therefor. .
Medical and Surgical Journal... was given of the difficulties met with in en
Metal Worker...... gineering construction at that day at points
Microscope, The........ remote from civilization. Considerable in
North American Review ..... teresting engineering data were presented, but the paper in general deviated somewhat
Political Science Quarterly.... from the strictly technical papers usually | OF SUPERIOR AND STANDARD QUALITY.
Popular Science Monthly.
Popular Science News....... presented, being of a more popular and en- Leading Nos.: 048, 14, 130, 135, 239, 333 Portfolio, The..... tertaining character.
Public Opinion ..
THE ESTERBROOK STEEL PEN CO., Puck ..
Works : Oamden, N.J. 26 John St., New York. Quarterly Review (London)....
Readers of Science Scientific American.......... Thomas D. Lockwood, member, entitled
Supplement........... “ Electrical Notes of a Transatlantic Trip."| Corresponding with or visiting Adver
Architect and Builders' edition..
Scribner's Magazine..... It embraced some observations on teleg-tisers will confer a great favor by mention Texas Siftings.........
Trained Nurse...... raphy; description of the London operating ling the paper.
She an mondorid on 0wndinne oooowwoning on
MP3 & 88.888
Does your Chapter want a good collection or Any person seeking a position for which he is quali- man about twenty years of age, to make working
library? fied by his scientific attainmen's, or any person seeking drawings of electrical instruments from free-hand
Sometimes there are not enough funds in sight some one to fill a position of its character, be it that sketches and verbal assistance. Must be able to
to make the purchase. If so, satisfactory arof a teacher of science, chemist, draughtsman, or what execute tinted drawings and tracings as well, and
rangements can be made by paying part with not, may have the 'Want' inserted under this head have
order and balance in small monthly payments. FREE OF Cost, if he satisfies the pubiisher of the suit. ciples of electrical measuring instruments. One able character of his application. Any person seeking
Where a collection already exists we will conwho has had some practice in brass and machine information on any scientific question, the address of work preferred, as also one who will remain and
tract to fill it out to any desired extent and any scientific man, or who can in any way use this col
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chapter. Address, stating salary expected, experience and paper, is cordially invited to do so.
To parties who cannot see our specimens here references, E. G. W., SCIEŃCE Office, N.Y. City.
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We issue no catalogues. CIANS. – The American Academy of
Old and Rare Books.
A. A, mineral collection. Medicine is endeavoring to make as complete a
64 large beautiful specimens, ready mounted, in list as possible of the Alumni of Literary Col.
Catalogue No. 29 nearly ready. Will contain
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"presents one of the 64 sub-divisions in Dana's have received the degree of M.D. All recipi. | many scarce works pertaining to Natural HisTables for the Determination of Minerals, ents of both degrees, literary and medical, are tory, Americana, out of print books, as a whole.
With each collection we send copy of Dana's requested to forward their names at once to Dr.
Manual and complete set of determination apR. J. Dunglison, Secretary, 814 N. 16th Street, interesting.
paratus with blow-pipe, acids, etc., etc. EveryPhiladelphia, Pa.
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thing first class. Price complete, $40.00 or
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MICHIGAN, HOUGHTON. former Assistant Editor of The Annals of MICHIGAN MINING SCHOOL. - For Catalogues Gynæcology, desires a position as instructor in "V address M. E. Wadsworth, A.M., Ph.D., Director.
Turns Nuts, Gas Burners or Pipe without adjustment. Physiology and Hygiene. Address “N, " 47
Made of Best Polished Steel. Sent by mail for 25 cts.
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