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A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



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UJNlVijltbAL btllljJNUllj LAJN ILKJN \q red LION STREET, LONDON, E.C. 



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Price £18. 



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GRIFFIN'S NEW FORM OF APPARATUS 



For the ABSOLUTE 



EXPANSION OF SOLIDS 



Weedons Patent i. 



One great iiterit in the design of this Apparatus is that it is a purely 

 Mechanical method, and does not depend at all upon Optical methods of 

 magnification that so frei|uently are a difficulty in early Practical Physics 

 iduces itself t J the readings of two Micrometer 



A DIRECT MECHANICAL METHOD. 



ABSOLUTE READINGS OBTAINED. 



SIMPLEST DESIGN. 



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THEN. C. S. PATTERN Of THE IROTTEk BAR PHOTOMETER. 



5 the Instrument selected by tin. 



tests on Incandescent Lamps (See Elcclri 



Much easier to read than either the shade 



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Price £9. 



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rumentdeli' 



unted Scale, for .«54 



General Po< ... 



iait, October 2, 1296, p. 738.) 

 V or grease-spot instrument. 

 100 Volt Standardised Lamp. 



Secohm, London." 



n U.S.A., but 



THE TOURIST'S ANEROID. 



For Measuring Altitudes without Calculation. 



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