Report of the Kew Committee. 



221 



1st period. Chronometer at temperature of 55° F. or 13° C. 

 2nd „ „ „ 70° „ 21° „ , 



3rd „ „ „ 85° „ 29° „ 



4th „ „ ,, 70° „ 21° „ 



5th „ 55° „ 13° ,, 



Certificates are granted to chronometers which have undergone 

 35 days' test as specified above, and whose performance is such 

 that : — 



1. The mean of the differences in each stage of the examination, 

 between (a) the average daily rate during that period, and (b) the 

 several daily rates, does not exceed one second in any one of the 

 stages. 



2. The mean daily rate has not been affected by change of tem- 

 perature more than one-sixth of a second per 1° F., which is about 

 a quarter of a second per 1° C. 



3. The mean daily rate has not exceeded ten seconds in any stage 

 of the test. 



A Kullberg's temperature regulator has been fitted by the maker to 

 the chronometer oven, and a Richard thermograph is also arranged 

 to work in the case with the chronometers, affording a continuous 

 record of the temperatures which they have experienced during the 

 whole of their trial. 



The range of temperature from 55° to 85° F., to which the marine 

 chronometers are submitted, has been decided upon after careful 

 consideration, as being amply sufficient for determining the behaviour 

 of chronometers under conditions to which they are usually exposed 

 at sea, and no serious objections have yet been received from makers 

 or others to the adoption of the above range. 



VII. Miscellaneous. 



Photographic Paper, 8fc. — This has been supplied to the Observa- 

 tories at Coimbra, Colaba, Falmouth, Lisbon, Mauritius, Stonyhurst, 

 and Toronto. It has also been supplied to the Meteorological Office, 

 the U.S. Navy Department, and others. 



Anemograph sheets have, in addition, been forwarded to Madras, 

 and bJank forms for the entry of observations to several persons. 



Extension of Building. — The Committee having decided on building 

 an additional floor on the east wing of the Observatory, for the pur- 

 pose of providing increased space for carrying on the Observatory 

 work, now very much cramped, have obtained from the Council the 

 promise of a loan of £200 if needed. 



Application has therefore been made to the Chief Commissioner of 

 Works and Public Buildings for permission to proceed with the work, 

 but the reply granting leave has not yet been received. 



