492 JOURNAL OF THE PLYMOUTH INSTITUTION. 
that place when the mean is taken over a very long time. Weather 
is changeable within very short periods ; climate is uniform except 
in its secular changes ; 7.e. for very long periods. Time enters as 
a factor into weather; from climate time has been eliminated. 
‘‘Climates are different in different places; whereas the weather, 
though changeable in any one place, may be the same at the same 
time in many places.” Thus we may consider climate as the 
integration of weather; and conversely, weather as the differential 
coefficient of climate. 
By meteorology, ‘‘ I understand the description and explanation 
of those phenomena which group themselves under the head of 
weather, of the seasons, and of climate.” (Sir J. Herschel ) 
Another writer (Dr. Mann) says, “Meteorology is the scientific 
study of atmospheric phenomena, and the investigation of weather 
and climate.” (Meteorological Lectures.) I hardly need to tell 
this audience that the term has not always been so restricted ; for 
at one time it was applied to the consideration of all appearances 
in the heavens, astronomical as well as atmospherical; and some 
have derived the term from meteors or falling stars; whilst others 
say it is derived from perewpos which signifies elevated or soaring. 
To obtain the climate of a place we must have organized and 
systematized meteorological observations extending over a very long 
period. Since I have been in Plymouth, I have endeavoured to do 
this for my adopted town, and I now offer to the Plymouth Insti- 
tution the results of my sixteen years’ work ; and I feel obliged to 
its members for accepting them, because with me it has been a 
labour of love. I am fully aware that all the instruments I have 
used (especially my rain gauge) are not so well placed as perhaps 
they would be, if someone who has greater facilities for exposure 
will take the matter in hand. I have done my best with: such 
means as I have at command, and failing all other consecutive 
observations mine must be accepted for what they are worth. 
GEOGRAPHICAL Position.—The situation of my house has been 
found from repeated astronomical observations to be in latitude 
50° 2232’ N., and longitude 4° 71’ W., and it is at the north-eastern 
end of the town, 69 feet above the mean sea level. Plymouth 
itself is situate a little to the south-west, but sufficiently near for 
the results here found to be taken for those of the town. It lies 
on the west bank of the estuary of the Plym, where it falls into 
