METEOROLOGICAL OBSERVATIONS AT PLYMOUTH. 149 



Third Itepori on the Progress of the Hourly Meteorological 

 Register at the Plymouth Dock-Yard, Devonport, Lat. 

 50° 21' 'N. Long. 4° 7' W., carried on at the request of the 

 British Association, under the direction of Mr. W. Snow 

 Harris, F.R.S. 



1. The Hourly Meteorological Observations, which the Council 

 of the British Association did me the honour to place under 

 my care, have been continued without interruption from the 

 early part of the year 1832. Since that time about 70,000 

 hourly observations on temperature have been completed, and 

 the results of several years printed in the Reports of the Asso- 

 ciation for 1835 and 1838. 



Similar observations of the barometer and moistened thermo- 

 meter commenced in January 1837, and briefly mentioned in 

 the Eighth Report of the Association, are now complete for 

 three years. In the present communication I propose to no- 

 tice some of the principal results of these registers. 



The registers of the anemometers invented by the Rev. Mr. 

 Whewell and Mr. Follett Osier, of Birmingham, although care- 

 fully attended to, have not been completed for a sufficiently 

 long period, owing to many difficulties and interruptions inci- 

 dental to the bringing of these instruments into operation. I 

 am not enabled, therefore, to say more at present of Mr. 

 Whewell's instrument than has already appeared in my former 

 Report. 



The observations hitherto registered by Mr. Osier's anemo- 

 meter have been tabulated by him in conjunction with those 

 registered at Birmingham ; they will appear in a separate form. 

 We may, however, now look forward to include the results of 

 all the instruments registered here in one general scheme. 



Hourly Register of the Barometer. 



2. In the three following tables will be found the principal nu- 

 merical results for the years 1837, 1838, and 1839, comprising 

 the mean hourly and monthly pressures, as also the mean 

 hourly pressures, for the four seasons, and for each six months 

 of summer and winter. From these we may obtain — 



1st, The mean pressure. 



2nd, The times of the day at which the mean pressure oc- 

 curs, and the mean daily course of the atmospheric tides, as 

 indicated by the hourly oscillation of the barometric column^ 



