480 



Report of the Kew Committee. 



Brought forward 1419 



Surveyor's Scales 33 



Theodolites . . 5 



Thermometers, Arctic , 43 



„ Avitreous or Immisch's 457 



,, Chemical 81 



Clinical 10116 



„ Deep sea 100 



„ Meteorological 1910 



Mountain 28 



„ Solar radiation 6 



Standards 64 



Unifilars 4 



Total 14266 



Duplicate copies of corrections have been supplied in 26 cases. 

 The number of instruments rejected on account of excessive 

 error, or which from other causes did not record with sufficient 



accuracy, was as follows : — 



Thermometers, clinical 38 



„ ordinary meteorological ] 6 



Various 50 



13 Standard Thermometers have also been calibrated, and 6 supplied 

 to different individuals during the year. 



There are at present in the Observatory undergoing verification, 

 10 Barometers, 850 Thermometers, 50 Hydrometers, and 8 Sextants. 



The increase in the number of sextants verified during the past 

 year has been considerable, 292 instruments of that kind having been 

 tested, whereas the greatest number in any previous year has been 

 157. A much larger number of artificial horizons has also passed 

 through the Department, being in nearly all cases flat glass plates set 

 in levelling frames and supplied with spirit levels. These have been 

 all Hall-marked after examination as to trueness of the surface. In 

 accordance with the arrangement mentioned in last year's Report, 

 440 Navy telescopes and binoculars have been examined and marked 

 for the Admiralty. Also 33 standard measures of length have been 

 tested for the War Office. 



The Committee, having considered the advisability of Hall-marking 

 other instruments besides the thermometers submitted to them for 

 verification, instructed Messrs. R. and J. Beck to construct for them an 

 engraving pantagraph, which has been fitted on the Holtzapffel lathe 

 belonging to the Observatory. By its aid the Navy telescopes, 

 binoculars, and Standard Rules have been successfully engraved with 

 mark and number. 



