clxx 



NATURE 



{Sept. 1 8, 1879 



NOTICE OF REMOVAL, 



JAMES HOW & CO., 



SCIENTIFIC INSTRUMENT MAKERS 

 73, FARRINGDON ST., LONDON 



(Late of 5, St. Bride St., and 2, Fostes Lane). 



HOW'S STUDENT'S MICROSCOPE. HOW'S MICROSCOPE LAMP. 



Rock Sections and other Objects for the Microscope. 



W. F. STANLEY, 



Mathematical Instrument Manufacturer 



To H.M.'s Government, Council of India, Science and Art 

 Department, Admiralty, &c. 



Mathematical, Drawing, and Surveying Instruments of every description, of 

 the highest quality and finish, at the most moderate prices. 



Price List post free. Engine Divider to the Trade, 

 ADDRESS- 

 GREAT TURNSTILE, HOLBORN, LONDON, W.C. 



THIN GLASS FOR MICROSCOPIC 



MOUNTING, of best quaHty, Circles, 3J. td. per ounce ; Squares, 

 2f. 9(/. ; post free ^d. extra ; Ground edged Slips, 5*. per gross ; also 

 other Mounting Materials and Objects prepared for mounting. — CHAS. 

 PETIT, 151, High Street. Stoke Newington. N. 



The LANCASTER POCKET CAMERA 



for plates 4} X 3I inch, having three double dry-plate Slides, Umbrella 

 Stand, best Lens with plate of Diaphragms, &c., &c., ;C5* Particulars 

 free- 



The LANCASTER CARTE PHOTOGRA- 

 PHIC APPARATUS, with Chemicals, &c., &c., complete, ;C3 5-f- 

 FIRST QUALITY ASTRONOMICAL TELESCOPES with Object 

 Lenses, by Wray, 2i-inch, £1 o^. ; 2j-inch, £,^ los. ; 2^-inch, ^lo ; 

 3-inch, ;£i2 10^.; 3j-inch, ;^i5 15J. ; 4-inch, ,jCz5 » 43-inch. £,^0', 

 5-inch, ;^55, &c. Capital Student's Rlicroscope, £-3^ 31. Collegian's 

 First Quality Microscope, ;£<; 5^. Illustrated Catalogue, 3 Stamps. 

 J. LANCASTER & SON, Opticians, Birmingham. 



JOHN NORMAN, 



MANUFACTURER OF 



MICROSCOPES, OBJECTS, CABINETS, 



TABLES, LAMPS, 



And all Glass Appliances for Microscopes, 



HAS OPENED NEW AND EXTENSIVE PREMISES AT 



34, 'Whitecross Street, Cripplegate, E.C. 



Lists post free on application. 



ELECTRICAL APPARATUS. ~ Science 



Teachers, Lecturers, and Amateurs, should send for Special Reduced 

 List. FRICTIONAL APPARATUS of new patterns and improved 

 insulation. HOLTZ MACHINES, warranted reliable in all weathers, 

 from ^4. Large set of Brass Induction Conductors, 2 12-inch Cylin- 

 ders, Sphere, Biot's Hemispheres, 6|-inch, ebonite mounted, 50J. Large 

 Uranium Glass Aurora Tubes. POWERFUL LEYDEN BAT- 

 TERIES, new construction, half cost of usual jars. VOLTAIC AP- 

 PARATUS. — Batteries, Quart Bunsen's, 4^. and 4J. 6(/. ^-ffa-l'on 

 Bichromate, 12 Cells, in Case, ;^8. Grove and all other Cells, MEDI- 

 CAL BATTERIES. ELECPRIC LAMP for lantern use, £(> 6s. ; 

 action equalling the most expensive. Cheaper Lamps. Coils, own 

 make, i-inch Spark, 73^- Bells, Wires, Carbons, and all requirements. 



F. H, BROOK, 107, Lorrimore Road, London, S,E. 



GOLD MEDAL, 



PARIS EXHIBITION. 



In Packets and Tins. Pure 

 Cocoa only, with the super- 



FRY'S 



COCOA 



fluous oil extracted. 



*If properly prepared, there is no nicer 

 or more wholesome preparation of 

 cocoa." — Food^ Water, and Air^ 

 edited by Dr. H assail. 



EXTRACT 



LIGHTNING CONDUCTOKS, 



Experience, accumulated rince the time of Benjamm Franklin, proves 

 conclusively that a Conductor made of Copper of adequate size is the best 

 of all appliances for the protection of every description of biuMing from the 

 destructive effects of lightning. 



J. S. FRY & SONS, Bristol and London. 



NEWALL & CO/S 



PATENT COPPER LIGHTNING CONDUCTOR, 



As applied to all kinds of Buildings and Shipping in all parts of the world 

 with unvarying success, is the most Reliable, roost Effective, and Cheape,- 1 

 Conductor ever offered to the public. 



It is stiuple in its application, no insulators bein^ required, and it c 

 only one shilling per foot for the standard sixe, which is safe in any storm. 



H- S. NEW^ALI. & CO., 130, STRAND, W.C. 



36, WATERLOO ROAD, LIVERPOOL 

 68. ANDERSTON QUAY, GLASGOW 



MANUFACTORY— GATESHEA.D-ON-TYNB 



0. TISLEY & Co. 



OPTICIANS, ■' 

 172, BROMPTON ROAD, S.W. 



(Close to South Kensington Museum). 



THE PHONEIDOSCOPE 



An Instrument for Observing the Colour-Figuresof Liquid Films under the 

 action of Sonorous Vibrations. 



Being a visible demonstration of the Vibratory and Molecular MotiotL of a 

 Telephone Plate. 

 The PHONEIDOSCOPE, with 3 Discs, Bottle of Solution, Descriptive 

 Pamphlet, &c., in Cardboard Box, 10s. 6d, 



MANUFACTURED AND SOLD WHOLESALE AND RETAIL BY 



S. C. TISLEY & CO., 172, BROMPTON ROAD, LONDON, S.W. 



TELEPHONIC ELECTRICITY. All Materiak supplied for experi- 

 mental purposes. 

 Price Lists 0/ Electrical and Acottstic Apparatus, with Drawings and 

 Description of the Hartnonosraph, Post Free, nd. 



NEW ILLUSTRATED CATALOGUE of ELECTRIC 



SIGNALS, &c., with Instructions for Fixing. 150 Diagrams. Just .ut, 

 post free, 6 Stamps. 



EDWARD PATERSON, 



Electrical Engineer and Scientific Apparatus Manufacture;; 



3, BEDFORD COURT, COVENT GARDEN, LONDON 



STEAM WORKS, GRAY'S INN ROAD. 



Experiments in Electric Lighting carried out. 



Electrical Apparatus of all Descriptions for Lecture Purposes Loatitd cut. 



APPARATUS for CLASS DEMONSTRATION and for SCIENCE 



SCHOOLS. 

 ELECTRIC LIGHT APPARATUS. 

 SIEMEN'S and GRAMME'S DYNAMO MACHINES and LAMPS 



for Hire and Purchase. 

 LARGE ASSORTMENT of RUHMKORFF COILS and VACUUM 



TUBES. 

 PROFESSOR HUGHES' MICROPHONE. 

 ELECTRIC BELLS and INDICATOR.^. 

 TELEPHONES and TELEPHONE CALL BELLS, WIRE, &c., for 



Fixing. 

 EDISON^S ELECTRIC PEN £i 8j. 



ELECTRIC and MAGNETIC APPARATUS of all Descriptions. 

 Illustrated Catalogue Electrical Apparatus, Part i. Post free, 6 Stanp?. 

 do do Electric Signals. Part 2. Post free, 6 Stamps. 



EUDOLPH KOENia^ 



(DR, PHIL.) 

 MANUFACTURER OF 



ACOUSTICAL INSTRUMENTS. 



TO ILLUSTRATE THE LAWS 



AND TO PRODUCE THE PHENOMENA OF SOUNI . 



PARIS, 26, EUE DE PONTOISE. 



PRICE LISTS FREE. 



