Report of the Kew Committee. 



453 



when its pattern shall have been definitely decided upon. Experiments 

 for this purpose are still in progress. 



The Committee finding that the " Hall Mark " for Thermometers was 

 not adopted by opticians, owing to the fact that a charge was made 

 for engraving it, decided, in December, to mark all Thermometers 

 verified at the Observatory free of cost. 



This resolution having been advertised in the leading scientific 

 journals, and a special assistant, H. Clements, having been engaged 

 for the purpose, the K. 0. monogram and register number have been 

 etched upon every Thermometer tested since the beginning of the 

 present year. 



As the "Hall Mark" advertisements caused numerous inquiries to 

 be made respecting the verification of instruments, the Committee 

 took advantage of the opportunity to issue a new and revised scale of 

 fees chargeable for this service. 



Air Thermometer. — The construction of the Standard Air Thermo- 

 meter has been delayed, in order that the Committee might be 

 enabled to adopt certain improvements which have been suggested by 

 Professors Thorpe and Riioker, who are at present engaged in mak- 

 ing an elaborate and accurate comparison between the mercurial and 

 air thermometers. 



At the invitation of Professor Thorpe, Mr. Whipple recently visited 

 the Yorkshire College of Science, Leeds, in order to witness the ex- 

 periments in progress. 



The difference between the old Royal Society Standard Barometer 

 and the Kew standards having been well determined, the daily com- 

 parisons were brought to a close in March last. The former instrument 

 is to be shortly returned to Burlington House, and again set up in the 

 apartments of the Royal Society. 



Owing to an accident to the Galton Thermometer-testing apparatus, 

 and the increased risk incurred in marking the Thermometers, the 

 breakage of Thermometers has been slightly larger than usual during 

 the past year, but it has only amounted to about one-half per cent, of 

 the total number verified. 



Some very old Standard Thermometers having been recently tested, 

 the Superintendent has been instructed to draw up an account of the 

 changes in their indications, for presentation to the Royal Society. 



A new form of thermometer has been designed by Mr. Whipple, and 

 constructed by Mr. Hicks, for the purposes of conveying indication of 

 temperature to a distance by means of electricity without the neces- 

 sity of employing intervening clockwork. Professor W. Gr. Adams 

 has kindly consented to make a set of experiments with this apparatus 

 in the laboratory of King's College. 



Waxed Paper, 8fc., supplied. — Waxed paper has been supplied to the 

 following Observatories : — 



