NATURE 



[May 1 1, 1905 



NEW DOUBLE 

 SURFACE CONDENSER. 



/^=" 



THE "IDEAL." 



This is the best and cheapest Conde 

 the market; all delicate parts are pi 

 by outer jacket, and the water cannc 

 to the distillate. Made in two • 

 and 8", 4/6 and 5/6 each. 



B*- Natu 

 pact and efficif 

 notice. We h; 



! says :- 



'Thi! 



of the 



com- 

 which has come before our 

 ted it for conden.sing such volatile 

 -ub^tances as ether, carbon disulphide, and acetone, 

 md have found that even with rapid distillation the 

 :ondensation is very complete. Generally speakinc, 

 n order to condense these substances satisfactorily, it 

 ploy a very long condenser ; of course, 

 ; a great amount of bench space. As 

 srs are used in a perpendicular posi- 

 in space is very great." 



SOLE MAKERS— 



BREWSTER, SMITH & CO., 



6 CROSS STREET, 



FINSBURY PAVEMENT, LONDON, E.C 



All kinds of Apparatus for Science Teaching, 



FREDK. JACKSON & Co. 



(Late MOTTERSHEAD & CO.), 



14 CROSS STREET, MANCHESTER 



Goods Entrance : 10 Half-Moon Street. 



LABORATORY FURNISHERS. 



Importers, Manufacturers, and Dealers In 



CHEMICAL AND PHYSICAL 

 APPARATUS 



Of every Description. 



Fine Chemicals, Volumetric Solntions, 

 Plain and Stoppered Bottles, 



AND EVERY LABORATORY REQUIREMENT, 



Illustrated Catalogue of Apparatus, with Prlec 



List of Chemicals, free on application. 



Telegraphic Address— " Apparatus, Manchester." 

 Telephone Number— jisS. 



SECOND-HAND TELESCOPES. 



6 ill. Dallmeyer Equatorial. Clock, complete, £100. 42 i". Alvan 



Clark, Equatorial by CoOke, £50. .Several :; in. Student Telescopes, by 



leadins makers, £4 lOs., £6 lOs., £8 lOs., £10. 



SECOND-HAND SPECTROSCOPES. 



Single, 2, and ; Prism, by Browning, £4 10s., £8 10s., £10. 

 SECOND-HAND MICROSCOPES. 



Watson's Edinburgh H., 3 powers and fittings, complete, as new, 



£16 lOs. Swift Army B.icteria, complete, £15. LeitZ ah, with rack, 



substage, and fittings, £6 10s. 



MANY OTHER.S. AM, KIND.S. LISTS ON APPLICATION. 



A.. cc.A.RZssora' £c co., 



28 BARTLETT'S BUILDINGS, HOLBORN CIRCUS, LONDON. 



ALFRED E. DEAN, 



THE LARGEST MAKER IN ENGLAND 



of Apparatus in all Departments of 



ELECTRO-THERAPEUTICS 



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 Oi 



82 



British and Foreign Hospitals, S:c. 

 LISTS ON APPLICATION. 



HATTON GARDEN, LONDON, 



COX'S IMPROVED 



HIGH FREQUENCY APPARATUS 



This apparatus, when 



working off a 10 in. Coil, 



will give from 800 to 1000 



milli amperes. 



_ Price, as illustrated. 



Mimii8ft^^---i. but with New Pattern 

 Spark Gap and New/ 

 Connections, 



Ctiaplin's Universal 

 Holder & Electrodes, 



£4 lOs. 



Full particulars of above, and all other forms of Electro- 

 Therapeutic Apparatus, are contained in our ILLUSTRATED 

 CATALOGUE in X-RAYS, &c. (including Instructions to 

 Beginners), post free. 



HAISR^y MV. COX, X^td., 



FACTORY ANIJ (.IFFICES— 



la ROSEBERY AVENUE, & 15-21 LAYSTALL ST., LONDON, E.C. 



G. BOW RON, 



57 EDGWARE ROAD, LONDON, W. 



SEOOND-HAND 



ELECTRICAL 

 AND PHYSICAL 



APPARATUS 



cost for lecturi 



o Ihe National Physical Laboratory ; Aberdeen, .\berystwytb 

 Nottingham and Glasgow Universities ; Bedford, Bradford 

 3t Watt and Yorkshire Colleges ; and twenty other Scientifii 

 Institutions, Polytechnics, &c. 



Teachers requiring efficient app; 



laboratory purposes, might 



ult the lis 



Accurate and 



Inexpensive. 



142 ST 



PIESMIG BAROMETER. 



To be obtained of all Opticians, or 

 the SOLE MAKERS. 



F. i>arto:n & CO., 



CLERKENWELL OPTICAL WORKS, 



JOHN STREET, LONDON, E.C. 



