C6S^'I^ 



A W 



EEKLV ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of Nature trusts the mind which builds for .^..."_^^ ORDSWORTH. 



^^;=;;;^;^^n:p^^^^?SS^^ 



i«^E"WTO!Ba' de CO., 



SCIENTIFIC INSTRUMENT 



MAKERS 



TO HIS MAJESTY THE 



KING 



AND THE GOVERNMENT. 



Philosophical Instku- 



MENT MAKEKS by SPECIAL 



Appointment to the 



Royal Institution of 



Great Britain. 



Makers of every descrip- 

 tion of OPTICAL and 

 PHYSICAL APPARA- 

 TUS of the highest class, 

 for Colleges, Institutions, 



A NEW 

 LENS 



ft' 



^^VHHEIL 0,1^ 



FOR ALL 



WORl-C 



In 3 Series. 

 I. GENERAL. 



4; 



#»y II. CONS t-RTIBLE. 



Vd in. StECIAL PROCESS. 



% 



CATALOGUE OF 



MACHINES. POST 



FREE. 



WIMSHURST ELECTRICAL MACHINES. 



Mudenf- pattern, 1= in.. 65s. Hest Quality, 



, ;£S ; -8 in., £6 ics. 

 Multiple-Plate Machines. £^c, 10^150. As made for the Science and 

 Ar^ Department, and ihe Univer-.il.. s of Oxford, Cambridge, Londcn, 

 SydneV. N.S.W., McGill, Montreal. &c.. &c. 



- FLEET =;TREET. TEMPLE B.\R. LOXDON, E.C. 



X-RAY TUBES 



Special arrangemert 

 for the 



This rapid, wide, medium or narrow angle lens all in one is 



suitable for all work. 



Full Catalogue free on application to the Manufacturers :— 



R. <Sc J. BECK, Lta., 



68 CORNHILL, LONDON, E.C. 



REGULATION OF THE 



HEAVY DISCHARGE 

 TUBES 



for use with 



ELECTROLYTIC 

 -> BREAKS. 



NEW PATTERN COMBINED 



BARO-THERMOGRAPH. 



■KW The abo%e in iriine-t - rlbin--- in .me apparatus ihe Recording Baro- 



Se/lCf for our ,t/-%^~e^ 1 „^,„ and Recording TheVmometer, giving thus on one and the same chart 



NiW Price List. ]h( continuous records of the atmospheric pressure and temperature for seven 



lliustratetl frkc lists of SacfiHc Instruments fnc l;v post to at', parts 



JOHN J. GRIFFIN & SONS, Ltd.. ' n e « HjLjilELVE.?.'' *• 



''0-''6 SARDINIA STREET, LINCOLN'S INN FIELDS, branches ■ 4= cornhill. .-md ,.. regent street 



LONDON. W.C. AWARDED TWO GOLD MEDALS PARIS EXHIBITION 1900 



