Page images
PDF
EPUB
[graphic]
[ocr errors]

DR. H. STROUD'S

Apparatus for
DETERMINING THE

VELOCITY OF
SOUND IN AIR, BY

THE METHOD
OF RESONANCE.

[ocr errors]

THE WILSON
SELF-REGISTERING

RAIN GAUGE,
JE Descriptive Circular

Post Free.
The Resonance Tube is 3 ft.
long, with a graduated scale
fixed at the side. The sliding The 'WILSON
reservoir moves easily in a

SELF-RECORDING
grooved frame, so that the water

level can be quickly altered. ELECTRICAL
Price, in Polished Mahogany RAIN GAUGE.
Stand, 24/-

Records auto-
matically on a

Weekly Chart.
SOLE MAKERS
BRADY & MARTIN, LTD., MAY BE OBTAINED THROUGH ANY OPTICIAN,

" If any difficulty be found in securing any of our Instruments Scientific Apparatus Makers,

through your Dealer kindly communicate with the Manufacturers,

PASTORELLI & RAPKIN, NEWCASTLE - UPON - TYNE.

(Established 1750), Makers and Dealers in all kinds of Chemical and Physical

Contractors to H.M. Government, Apparatus for Schools and Colleges, Works' Laboratories and Special Research Work.

46, HATTON GARDEN, LONDON, E.C. CONSTRUCTION OF NEW FORMS OF APPARATUS

Telephone No. 1981, Holborn. Telegrams-"Rapkin, London." UNDERTAKEN,

ACTUAL WHOLESALE) MAKERS OF ALL KINDS OF METEOROLOGICAL INSTRUMENTS.

MET

LISTE

[ocr errors]

CHARLES GRIFFIN & CO., LTD.,

NEW BOOKS AND NEW EDITIONS.

PUBLISHERS.

Write for Circular.

VOLUMETRIC
APPARATUS

Now Ready. Second Edition, Revised and Enlarged. Very Fully

Illustrated. 255. net.
THE METALLURGY OF STEEL.

By F. W. HARBORD. A.R.S.M., F.I.C.
With a section on The Mechanical Treatment of Steel, by J. W.
Hall, A.M.I.C.E. With 37 Plates, 28o lilustrations in the Text, and

nearly 100 Photo-micr graphs of Steel.
Just Out. In Large Crown 8vo, with 201 Illustrations. 6s. net
AN INTRODUCTION TO THE DESIGN OF BEAMS, CIRDERS,
AND COLUMNS IN MACHINES AND STRUCTURES.

By W. H. ATHERTON, M.Sc., M.I. Mech.E.
In Medium 8vo. Handsome Cloth. With over 100 Illustrations. 1os. 6d. net.

CONSTRUCTIONAL STEELWORK:
Being Notes in the Practical Aspect and the Principles of Design. Together
with an Account of the Present Methods and Tools of Manufacture.

By A. W. FARNSWORTH, A.M.I.Mech.E.

In Large Crown 8vo. Cloth. Fully Illustrated. 55. ner.
OIL FUEL : Its Supply, Composition, and Application.

By SYDNEY H. NORTH,

Late Editor of the "Petroleum Review.'
“Everyone interested in this important question will welcome Mr. North's
important Text Book "- Nature.
In Medium 8vo. Handsome Cloth. Illustrated. 155. net.

CALCAREOUS CEMENTS:
Their Nature, Manufacture and Uses, with some Observations upon

Cement Testing.
By GILBERT R. REDGRAVE, Assoc.I.C.E., and

CHARLES SPACKMAN, F.C.S.
"One of the standard works on the subject."-Surteroi.

In Large Crown 8vo. Fully Illustrated. 6s. net
THE INVESTIGATION OF MINE AIR:
An Account by several Authors of the Nature, Significance, and Practical
Methods of Measurement of the Impurities met with in the Air of Collie ries

and Metalliferous Mines
Edited by Sir C. LE NEVE FOSTER, D.Sc., F.R.S., and

J. S. HALDANE, M.D., F.R.S.

Verified and Stamped

at the NATIONAL PHYSICAL

LABORATORY.

JOHN J. GRIFFIN & SONS, Ltd.,
SARDINIA STREET,

LONDON, W.C.

THURSDAY, MAY 1, 1905.

three following laws :-(1) A certain number of hydrological facts, corresponding to the low stages, or

minima discharges, of springs or watercourses, in FLOW OF UNDERGROUND AND RIVER

many cases depend almost exclusively on the total

rainfall of several preceding warm and cold seasons. WATERS.

It is only in the case of restricted watersheds that the Essais d'Hydraulique souterraine et fluviale. By

rainfall of the last one or two cold seasons exercises Edmond Maillet, Ingénieur des Ponts et Chaussées.

a predominating influence, the number of preceding Pp. vi+218. (Paris : Librairie scientifique, A. Her

1 years on which the results depend increasing in promann, 1905.) Price in francs.

portion to the size of the basin. The preceding warm THIS treatise, which was presented in the first seasons have less influence than the following cold 1 instance to the Academy of Sciences of Paris in seasons; and they both have less influence in propor1903, is divided into two parts, the first theoretical and tion as they date further back, though this loss of the second practical, to which a paper has been influence varies inversely with the size of the basin. appended, mainly of a practical nature, on the curves | The immediately preceding spring and summer rainof the discharge of springs and the abatement of river falls may introduce an element of disturbance if they floods. The book is addressed to mathematicians, are heavy and widespread, supposing that the perphysicists, geologists, geographers, meteorologists, meable strata predominate in the basin; but where the engineers, and all who are interested in the motion basin is almost wholly permeable, the rainfall of the and the distribution of rainfall, both on the surface preceding warm seasons may often be neglected. of the land and underground; and its object is to (2) The lowest level at a given point of a watercourse investigate theoretically and practically the variations in any year is approximately a function of the miniin the discharge of springs, and the low-water flow mum level of the preceding year, and of the amount of rivers, in order to be able to foretell the amount of of rain during the preceding cold season, and some this minimum flow, precisely as the height of the preceding months of the warm season is very wet or floods of rivers is predicted, as already effected in very dry, provided the proportion of impermeable certain cases by French hydraulicians, such as strata in the basin is small. In the case of many Dupuit, Belgrand, Lemoine, de Preaudeau and others, watercourses, the minimum yearly level varies little and also recently by the author with respect to two from year to year; and a succession of several years, of the sources of the River Vanne.

or several cold seasons, more rainy or more dry than M. Maillet believes that he is the first to have in the average, is needed to produce modifications, dicated a method by which exact quantitative dis- which, moreover, are slow and progressive with the charges can be systematically predicted, such as a lapse of time. (3) In the Seine basin, the low-water

Taphic curve, based upon Dausse's law concerning levels at given points of many of the watercourses the permeable strata of the Seine basin, enabled him draining almost wholly permeable strata, differ little to determine the yearly minima discharges of two from their mean secular height. These variations sources of the Vanne several months beforehand. | cannot be abrupt, except under the immediate inLater on, by means of the hypothesis of a particular fluence of rainy summers on the impermeable strata form of the free water-surface, he succeeded in obtain of the basin; and in any case they would be proing a law which proved to be in accordance with ex gressive, as a result of a gradual increase in the mean perience, as indicated in the first half of the theoretical rainfall for a certain number of years. Subject to portion of the book. In the second half of this por- these reservations, an appreciable variation in the tion, the stability, or the nature of the motion of low-water level must be due to other than meteorunderground waters, under different conditions, is ological causes. investigated, allowing for the increase in volume pro- The second. practical, part of the book occupies duced by rain; and assuming a simple form for the little more than a third of the space devoted to impermeable bed over which the water flows, it is theoretical considerations, though divided into ten shown that where the line of the bed is convex up- chapters, which are, consequently, very short for the wards the maximum height of the flood will be rapidly most part. It contains some practical applications of attained, and where concave, the flood will rise slowly, the views and theories developed in the first part, to and that the influence of a part of the stream on the the prediction of various hydrological phenomena, and maximum will be greater in proportion to the fall of also some experimental verifications; and the works the bed. The connection, also, between the low-water of Belgrand, and the observations and publications of leeks, or minima discharges, at any point of a water. the hydrometric service of the Seine basin, form the course or spring and the rainfall, is considered in as basis of this inquiry. After a very brief introduction, general a form as possible, and it is proved that, in the chapters deal successively with proportion of rainpractice, the lowest discharge may often be regarded fall which feeds underground waters, prediction of the Is a function of the combined rainfall of the preceding 'drying up of the sources of the Somme from the rainhot and cold seasons, and experiences very light fall, prediction of the discharges of Cerilly spring, a variations from year to year, especially in large river source of the Vanne, prediction of the minima diy basins, unless the warm season is very rainy and im- charges of the source of the Vanne, application to perineable strata intervene.

the sources of the Dhuis, prediction of the low-water The results of the theoretical investigations com- levels of the Marne at La Chaussée, drying up of the prised in the first six chapters are summed up in the i Laignes, remarks on springs uppising Havre, and

[graphic]
[ocr errors]

BIRKBECK COLLEGE
BREAM BUILDINGS, CHANCERY LANE, E.C.
FACULTY OF SCIENCE,
DAY AND EVENING COURSES.

J. E. MACKENZIE, Ph.D., D.Sc Chemistry . . . H. WREN, Ph.D., B.A., B.Sc.

ALBERT GRIFFITHS, D.Sc. Physics ... ..

D. OWEN, B.A., B.Sc.

B. W. CLACK, B.Sc. Mathematics

E. H. SMART, M.A.

W. G. BIRT, B.A., B.Sc.

JA B. RENDLE, M.A., D.Sc. Botany ... ..

" F. E. FRITSCH, Ph.D., B.Sc. Zoology ...

... .. H. W. UNTHANK, B.A., B.Sc. Geology & Mineralogy Geo. F. HARRIS, F.G.S. Assaying, Metallurgy & Mining, Geo. PATCHIN, A.R.S.M.

RESEARCH in Chemistry and Physics in well-equipped laboratories. French, German, Spanish, Russian, Dutch, & Italian Classes,

EVENING CLASSES also in Biology, Physiology, Practical Geometry, Building and Machine Construction, Steam, Tbeoretical and Applied Mechanics, Land and Quantity Surveying, and Estimating.

Calendar 6d. (post free Bd.), on application to the SECRETARY.

[graphic][merged small][merged small][subsumed][merged small][merged small][subsumed][merged small][merged small][subsumed][merged small][subsumed][subsumed][merged small][merged small]

W. WILSON.

VERNIER

MICROSCOPE.

THE SYTAM SYSTEM

Saves an incredible amount of wall space and

completely utilises dark corners, recesses, and Horizontal and Vertical Scales ;

out-of-the-way places. 16 cm. in length. The microscope

Prevents crowding and confusion.
rotates on a horizontal axis, and Allows for extension as and when required.
can be clamped in any position. Always room for more, hence reorganisation

One power and one Eye-piece. seldom or never necessary.
With Scales reading to 'l mm. £6 10

Saves time, lightens work, and increases comfort , '05 , 70 by producing perfect order in the Laboratory,

Library, Study, Home, Office, &c. .01 , 8.5

SOME SYTAM FITTINGS. I BELMONT STREET, CHALK FARM, N.W.

1. THE BOTTLE ELEMENT.

One hundred 4 oz. bottles are arranged in one Sytam Bottle - Element occupying less than 1 sq. ft. of wall space, each bottle is instantly

located, removed or replaced, and any size from OF THE HIGHEST ACTIVITY

1-oz. to a Winchester can be accommodated in IN 5 mg. TUBES.

one and the same element. Only a Few Tubes left.

2. THE CLOSED-FRONT BOOK ELEMENT. ARMBRECHT, NELSON & CO., 3. THE OPEN-FRONT BOOK ELEMENT. 71 & 73 DUKE STREET, GROSVENOR SQUARE, W.

4. THE AUTHOR'S FILE. Telephone: GERRARD, 1942.

For division of subject into headings, chapters

or sections, 18-inch Apps-Newton Coil for sale, in perfect condition. No trace of oxidation on the vulcanite. G. BOWRON,

5. THE TWIN DESK TRAYS. 57 Edgware Road, W.

6. THE PAMPHLET FILE. Metallurgical Laboratory, well equipped for experimental work, to let at low rent. One minute from Station.

THE SYTAM FITTINGS CO., Fifteen minutes to City. Apply MARSHALL & Co., Campbell Works, oke Newington, N. (close to Station, G.E.R.). Tel., 79 Dal-ton. 18 & 19 BASINGHALL

RADIUM BROMIDE

NEW DOUBLE SURFACE CONDENSER.

THE “IDEAL."

COX'S IMPROVED HICH FREQUENCY APPARATUS

[graphic]

This is the best and cheapest Condenser on the market; all delicate parts are protected by outer jacket, and the water cannot over. flow into the distillate. Made in two sizes, 6"

and 8", 4/6 and 6/6 each.

This apparatus, when working off a 10 in. Coil, will give from 800 to 1000

milli amperes.

ir NATURE says :-“This is one of the most compact and efficient condensers which has come before our notice. We have tested it for condensing such volatile substances as ether, carbon disulphide, and acetone, and have found that even with rapid distillation the condensation is very complete. Generally speaking, in order to condense these substances satisfactorily, it is necessary to employ a very long condenser ; of course, this means using a great amount of bench space. As the new condensers are used in a perpendicular position, the saving in space is very great.'

[ocr errors]

Price, as illustrated, URL but with New Pattern

Spark Gap and New
Connections,

£12.

SOLE MAKERSBREWSTER, SMITH & Co.,

6 CROSS STREET, FINSBURY PAVEMENT, LONDON, E.C. All kinds of Apparatus for Science Teaching.

Chaplin's Universal Holder & Electrodes,

84 10s.

[blocks in formation]

Full particulars of above, and all other forms of ElectroTherapeutic Apparatus, are contained in our ILLUSTRATED CATALOGUE in X-RAYS, &c. (including Instructions to

Beginners), post free.

Goods Entrance : 10 Half-Moon Street.

Apparatus for estimation of sulphur in

Importers, Manufacturers, and Dealers in
CHEMICAL AND PHYSICAL

APPARATUS
Of every Description.
Fine Chemicals, Volumetric Solutions,

Plain and Stoppered Bottles, AND EVERY LABORATORY REQUIREMENT, Illustrated Catalogue of Apparatus, with Price

List of Chemicals, free on application. Telegraphic Address-"APPARATUS, MANCHESTER."

Telephone Number—7238.

[merged small][graphic][subsumed][subsumed]
[ocr errors]

SECOND-HAND TELESCOPES. 6 in. Dallmeyer Equatorial, Clock, complete, £100. ad in. Alvan Clark, Equatorial by Cooke, £50. Several 3 in. Student Telescopes, by

leading makers, £4 10s., £6 10s., £8 10s., £10. SECOND-HAND SPECTROSCOPES. Single, 2, and 3 Prism, by Browning, £4 10s., £8 10s., £10.

SECOND-HAND MICROSCOPES. Watson's Edinburgh H., 3 powers and fittings, complete, as new, £16 10s. Swift Army Bacteria, complete, £15. Leitz 2b, with rack,

substage, and fittings, £6 10s. MANY OTHERS, ALL KINDS. LISTS ON APPLICATION.

A. CLARKSON & CO. 28 BARTLETT'S BUILDINGS, HOLBORN CIRCUS, LONDON.

[merged small][merged small][graphic][merged small]

ALFRED E. DEAN,

[ocr errors]

THE LARGEST MAKER IN ENGLAND

of Apparatus in all Departments of

ELECTRO-THERAPEUTICS

THE NEW PATENT

Including Radiography, High Frequency, Hydro-Electric and Light Baths, Finsen and other Light, Cautery, Electrolysis, &e.

INDUCTION COILS AND STATIC MACHINES A SPECIALITY. CONTRACTOR TO THE WAR OFFICE, INDIA OFFICE, AND ADMIRALTY,

BRITISH AND FOREIGN HOSPITALS, &c.

LISTS ON APPLICATION.

PIESMIC BAROMETER.

Descriptive

To be obtained of all Opticians, or Pamphlet

the SOLE MAKERS Post Free.

F. DARTON & CO.,

CLERKENWELL OPTICAL WORKS,

« PreviousContinue »