WATKINS & DONCASTER,

Naturalists and Manufacturers of CABINETS AND APPARATUS

FOR ENTOMOLOGY, BIRDS' EGGS AND SKINS, AND ALL
BRANCHES OF NATURAL HISTORY.

SPECIAL SHOW-ROOM FOR CABINETS.
N.B. For Excellence and Superiority of Cabinets and Apparatus, refer-
ences are permitted to distinguished patrons, Museums, Colleges, &c.
A LARGE STOCK OF INSECTS, BIRDS' EGGS AND SKINS.
SPECIALITY.-Objects for Nature Study, Drawing
Classes, &c.

Birds, Mammals. &c., Preserved and Mounted by First-class Workmen true to Nature. All Books and Publications on Natural History supplied. 36 STRAND, LONDON, W.C. (Five Doors from Charing Cross.)

New Catalogue (102 pp.) just issued, post free.

ALBERT

EDWARD JAMRACH

(Late CHARLES JAMRACH),
NATURALIST,

180 ST. GEORGE STREET EAST. Implements of Savage Warfare, Idols, Sacred Masks, Peruvian Pottery, Netsukis China, Lacquers, Gongs, Shells, and other Curios.

MICROSCOPICAL PETROGRAPHY.

Gentlemen interested in the above study are invited to send to JAMES R. GREGORY & CO.,

1 Kelso Place, Kensington Court, London, W., for a Prospectus of

THE TWENTIETH CENTURY ATLAS OF
MICROSCOPICAL PETROGRAPHY,
now being issued in Twelve Monthly Parts, each Part containing Four Fine
Half Tone Plates, and also Four actual Rock Sections.

Subscription in advance, either Monthly, 7/-; Quarterly, 21/-; or for the whole Series of 12 Monthly Parts & 48 Sections, £4 4s.

LIVING SPECIMENS FOR

THE MICROSCOPE.

Volvox, Spirogyra, Desmids, Diatoms, Amoeba, Arcella, Actinosphærium, Vorticella, Stentor, Hydra, Floscularia, Stephanoceros, Melicerta, and many other specimens of Pond Life. Price 15. per Tube, Post Free. Helix pomatia, Astacus, Amphioxus, Rana, Anodon, &c., for Dissection purposes. THOMAS BOLTON,

25 BALSALL HEATH ROAD, BIRMINGHAM.

MARINE BIOLOGICAL ASSOCIATION
OF THE UNITED KINGDOM.
THE LABORATORY, PLYMOUTH.

The following animals can always be supplied, either living or preserved by the best methods :

Sycon; Clava, Obelia, Sertularia; Actinia, Tealia, Caryophyllia, Alcy. onium; Hormiphora (preserved); Leptoplana; Lineus, Amphiporus, Nereis, Aphrodite, Arenicola, Lanice, Terebella; Lepas, Balanus, Gammarus, Ligia Mysis, Nebalia, Carcinus; Patella, Buccinum, Eledone, Pectens Bugula, Crisia, Pedicellina, Holothuria, Asterias, Echinus. Ascidia, Salpa (preserved), Scyllium, Raia, &c., &c. For prices and more detailed lists apply to Biological Laboratory, Plymouth.

THE DIRECTOR.

THE NEW COLLECTION OF

336 SPECIMENS AND SLIDES OF ROCKS,

according to H. ROSENBUSCH: "Elemente der
Gesteinslehre, 2d ed. 1901."

Accompanied by a text-book: "Practical Petrography," giving a short
description of the polarizing microscope and its application, and also of the
macroscopical and microscopical features of every specimen of this collec-
tion, by Professor Dr. K. Busz of the University of Münster. This
collection is intended for the practical use of students, and contains typical
representatives of all important types of rocks; it is composed of 277
massive rocks (94 deep-seated rocks, 50 dike rocks, 133 volcanic rocks),
28 sedimentary, and 31 crystalline schists. Out of it two smaller collections
of 250 and 165 specimens have been selected. The prices are as follows:-
Collection I. 336 Specimens of Rocks 380 Marks.
Ia. 336 Slides ...
420
270

II. 250 Specimens of Rocks IIa. 250 Slides...

310

ROCKS, MINERALS, FOSSILS. For Collectors, Students, Technical Schools, Colleges, &c. COLLECTIONS IN POLISHED DEAL BOXES.

25 Specimens, 5/6; 50 do., 10/6; 1oo do., 21/-; 200 do., 42/20 Coal Measure Rocks and Fossils, 12/6; do., larger, 15/-. Adapted for the Board of Education Examinations in Geology, Physiography, and Mineralogy.

A large stock of Minerals, Rocks, Fossils and Microscopic Objects for selection. Specimens sent on approval.

Cabinets, Geologists' Hammers, Chisels, Card Trays, Glass-capped Boxes, Models of Crystals, &c., &c.

NEW CATALOGUE POST FREE.

THOMAS D. RUSSELL, 78 Newgate St., London, E.C.

Education Offices,

G. L. GOMME,

Clerk of the London County Council.

Victoria Embankment, W.C., June 1, 1905. METROPOLITAN WATER BOARD. DIRECTOR OF WATER EXAMINATIONS. The Metropolitan Water Board are about to appoint on their permanent staff a Chief Officer who will be styled DIRECTOR OF WATER EXAMINATIONS, and whose duties will be to advise the Board as to the buildings, equipment and staff to be provided (under section 25 of the Metropolis Water Act, 1902), and subsequently to take charge and supervision thereof. The Director will also be required to give his whole time to the work, and to superintend and be responsible to the Board for all examin. ations, analyses, experiments and reports, and to undertake such research work and chemical analyses and bacteriological investigations, whether of water or otherwise, as may from time to time be required of him by the Board. The appointment will be held during the pleasure of the Board, and the salary will be £1000 per annum.

Applications for the appointment must be made in writing, and must state the age, qualifications, experience and present occupation of the applicants. Official forms of application may be obtained from the undersigned, and should be used if practicable.

Applications must be enclosed in sealed envelopes endorsed "Director and addressed to the undersigned; the last day for receiving them is Tuesday, July 11, 1905.

Canvassing members of the Board will be strictly prohibited and will be regarded as a disqualification.

Savoy Court, Strand, W.C., May 31, 1905.

A. B. PILLING,

Clerk of the Board.

ROYAL SCOTTISH GEOGRAPHICAL SOCIETY.

The SECRETARYSHIP of this Society will be Vacant on August 31. Salary, £200 per annum. The gentleman holding the office would require to be willing to give his whole time to its duties. Written applications, stating age, qualifications, references, &c., should be addressed to "THE HONORARY SECRETARIES, GEOGRAPHICAL SOCIETY, I Queen Street, Edinburgh," not later than June 26, 1905.

It is particularly requested that there be no canvassing of Members of Council.

BIRKBECK COLLEGE.

The Council invite applications for the appointment of ASSISTANT LECTURER IN MATHEMATICS. Commencing Salary £175, to date from September 1 next. Applications, stating age, degrees and qualifications, teaching experience, and enclosing testimonials, must reach the PRINCIPAL not later than Tuesday, June 20.

Birkbeck College,

Breams Buildings, Chancery Lane, E.C.

TO SCIENCE AND MATHEMATICAL MASTERS.-Required (1) For Technical School, Special Subjects, Electro Technics and Electricity, £160 to £200. (2) Chemistry, Physics, Mechanics, and Maths., £120, resident, or the post might be non-resident. School in Ireland. (3) Well-qualified Master to teach Electricity, must have had experience in the organisation of the work of a Local Technical Instruction Committee, £150 to £200. (4) Graduate, or A.R.C.S. for Chemistry, Physics, and Mechanics, £100, resident. Endowed Grammar School. (5) Maths., Chemistry, and Physics, £120. County School. For particulars of the above and many other vacancies, address GRIFFITHS, SMITH, POWELL & SMITH, Tutorial Agents (Estd. over 70 years), 34 Bedford Street, Strand, London.

Botany

J. E. MACKENZIE, Ph.D., D.Sc. H. WREN, Ph.D., B.A., B.Sc. (ALBERT GRIFFITHS, D.Sc. ...D. OWEN, B.A., B.Sc. B. W. CLACK, B.Sc.

...

E. H. SMART, M.A.
W. G. BIRT, B.A., B.Sc.

JA. B. RENDLE, M.A., D.Sc. 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, Theoretical and Applied Mechanics, Land and Quantity Surveying, and Estimating. Calendar 6d. (post free 8d.), on application to the SECRETARY.

UNIVERSITY

OF

BIRMINGHAM.

FACULTY OF SCIENCE.
RESEARCH SCHOLARSHIPS.
Each of the value of about £96.

(Founded by the late T. AUBREY BOWEN, Esq., of Melbourne, Australia.
(a) Two BOWEN SCHOLARSHIPS in ENGINEERING.
(b) One BOWEN SCHOLARSHIP in METALLURGY.

(c) Three PRIESTLEY SCHOLARSHIPS in CHEMISTRY. The object of these Scholarships is to encourage higher work and research in Scientific Professional Engineering and in Chemical and Metallurgical Science. Applications, supported by details of educational training, and references to former teachers and others, should be sent to the REGISTRAR on or before June 19, 1995. The Scholarships will be tenable during the Session 1905-6. Further particulars may be obtained on application to the REGISTRAK. UNIVERSITY OF CAMBRIDGE. LONG VACATION COURSE, 1905.

PATHOLOGY, PUBLIC HEALTH AND PHARMACOLOGY. This year the work of the Long Vacation Course will be divided into three sections: (1) (for D.P.H. Students) commencing on Monday. June 26, and (2) (for Junior Students of Medicine) and (3) (for Advanced Students, Medical Men, Veterinary Surgeons, &c.) commencing on Monday, July 3

Any further information may be obtained from Mr. E. E. STUBBINGS, Pathological Laboratory, Medical School, Cambridge. Cambridge, May 19, 1905.

NORTHAMPTON INSTITUTE,

ST. JOHN STREET ROAD, LONDON, E.C. The Governing Body invite applications for the following vacant appointMECHANICAL ENGINEERING DEPARTMENT. DRAWING OFFICE and LECTURE ASSISTANT, full time. Salary, 120 per annum.

PATTERN MAKER and INSTRUCTOR in PATTERN MAKING, full time. Salary, £120 per annum.

JUNIOR DRAWING OFFICE INSTRUCTOR, full time. Salary, £100 per annum.

LABORATORY DEMONSTRATOR for the Engineering Laboratories, full time.

JUNIOR TECHNICAL ASSISTANT, full time. EVENING INSTRUCTOR in AUTOMOBILE WORK. two evenings per week.

ELECTRICAL ENGINEERING DEPARTMENT.
JUNIOR TECHNICAL ASSISTANT. full time.
JUNIOR LECTURE ASSISTANT, full time.

Further particulars of any of the above, with forms of application, which should be returned not later than 10 a. m. on Thursday. June 29, 1905, can be obtained on application by letter to

R. MULLINEUX WALMSLEY, D.Sc., Principal. For other Scholastic Advertisements, see fage liv.

DR. H. STROUD'S

Apparatus for

DETERMINING THE
VELOCITY OF

SOUND IN AIR, BY
THE METHOD
OF RESONANCE.

The Resonance Tube is 3 ft.

TRADE MARK

Tabloid' Brand

Metol-Quinol

Developer.

Equally good for plates, films, bromide papers, gaslight papers and lantern slides. Economical and compact: portable and keeps.

Sold by all dealers and chemists.
WRITE FOR BOOKLET GRATIS.

BURROUGHS WELLCOME AND CO.,
LONDON, SYDNEY AND CAPE TOWN.
Chief Offices-Snow Hill Buildings, London.

Price

Telescope and prism table reading to I min.; clamp and fine adjustment to both. Rack-motion to telescope; prism table adjustable vertically and horizontally. Adjustable slit to colli mator. Protected circle. In case. £6 0 0

fixed at the side. The sliding reservoir moves easily in a grooved frame, so that the water level can be quickly altered. Price, in Polished Mahogany Stand, 24/

SOLE MAKERS

BRADY & MARTIN, LTD.,

Scientific Apparatus Makers, NEWCASTLE-UPON-TYNE.

Makers and Dealers in all kinds of Chemical and Physical Apparatus for Schools and Colleges, Works' Laboratories and Special Research Work.

CONSTRUCTION OF NEW FORMS OF APPARATUS UNDERTAKEN.