g^ummav)j of ififleteoro logical <©i)girrbatious 



EEGISTERED AT THE 



EOYAL INSTITUTION OF CORNWALL. 



Some years have elapsed since it was determined by the Council 

 of the Royal Institution of Cornwall that a summary of the 

 meteorological observations made and recorded at their Museum 

 should be prepared, and presented to the members ; and the work 

 was entrusted to my care. Unavoidable delay has occurred ; but 

 it has been of some advantage by adding to the series the years 

 1880 and 1881, which have been marked by some interesting 

 peculiarities. 



The observations recorded extend from 1840 to 1881, inclusive ; 

 but it is only since the beginning of 1850 that the instruments have 

 been placed as they are at present ; and it has been thought best, 

 while shewing the annual results in regard to temperature during 

 the whole term, to limit the full tabular statement, — combining in 

 one view all principal meteorological elements, and exhibiting the 

 results for each month separately, — to the period of thirty-two years 

 throughout which the conditions have been identical. Those con- 

 ditions are as follows : — 



The barometer is a standard made by Barrow, and compared 

 with the standard barometer at the Royal Observatory, Greenwich, 

 by Mr. Glaisher. It is hung on a north wall in the Museum ; and 

 corrections for Index error ( + o"oo8), capillarity (+0,013), height 

 above mid-tide (43 feet), and temperature have been applied. 



The thermometers are hung in a hexagonal wooden shed, 7 

 feet in height, 3 feet 6 inches in width, and 2 feet 6 inches from front 

 to back, with conical roof placed on the flat leaden roof of 

 the Museum, with single louvres 4 inches wide, inclined out- 

 wardly in the sides at an angle of 50 degrees, above the level 

 of 4] feet 2 inches, with interspaces of 2j^ inches vertical, 

 between which the air passes freely, the part below being 

 pierced by numerous holes i inch in diameter. The Dry 



