RAIRD &.TATLOCK (LOM)ON) LTD. 



Thermometers of Finest English Manufacture 



To reduce Centigrade degrees to Fahrenheit, multiply by 9, divide by 5, and add 32. Example 20 C 



< 9 -f 5 + 32 = 68 F. 



To reduce Fahrenheit degrees to Centigrade, subtract 32, multiply by 5, and divide by 9. Example 104 F 

 - 32 X 5 -r 9 = 40 C. 



THERMOMETRICAL EQUIVALENTS. 



Cent. Fahr. 



3I5.55 180 



260 150 



204.44 100 



149 60 



130 32 



Fahr. 

 600 

 500 

 400 

 300 

 266 

 212 



= IOO C 



CERTIFICATE- 

 OF 



EXAMINATION 



Catlerd ThtraoiMtvr /V0 13Z38 

 bird 4 Tttlook (London) Ltd. 



Corrtcntnt (t* tl* ntartti ) to k applud n th RtmJmgt, 



dttermmtd by com far u ft -u/irh tht Standard f/utr*mr*tj of 



Vbc ^Rtitnol flhijiutl 



Hot* II. * ' 



Th oflrraotlOT.* ftbori 

 ptln< 444.& C. foi 



rfr to tb lr Mftlt, 

 point 



IbT ] 



,9 09- 



Cent. 

 = 82.22 



65.55 

 37-77 

 15-55 

 o 



= -17-77 



We give on pages following a selection of thermometers in several grades. They are of first -class make 

 (1 carefully calibrated. The tubes only are kept in stock ready for graduating as required. Time required 

 r delivery, ordinary and standard thermometers, two or three weeks ; thermometers with 

 ational Physical Laboratory Certificates, four to five weeks, according to the time taken in 



^andardising. We are prepared to make any thermometer to specification, and the list is intended as a 



i ide to selection. 



N.B. The National Physical Laboratory test all thermometers by immersion up to or within 

 i negligible distance of the end of the mercury column. 



1 CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 



767 



