36 
tlEPont—i8o4. 
The mean temperature of the earth at this latitude is theoretically Calculated at 
58° *, but from the mean daily observations for ten years taken twice a-day, or the 
two extremes of night by a self-registering thermometer, and by actual observation 
at noon, it is found to be 41°'94 at the mines, or 16° colder than theoretically esti¬ 
mated, owing chiefly to its position on the east side of the continent, and to the 
cooling influence of the sea breezes during the summer months. 
The mean temperature of the year is found to vary in different years to the eitcnt 
of 3£°, but the observations have not been extended through a sufficient number oi 
years to know whether the fluctuations are periodical or not. 
159° have been observed under the full influence of the sun’s rays, and 40 hdov 
zero were observed at the bottom of the coal pit (230 feet deep) when the thermo¬ 
meter on the surfnee registered 22°. . ■ 
The greatest heat that has been observed in the shade G feet above tue groun 
was 98°, and the greatest cold 22° below zero, giving an extreme range of I- • 
By dividing the vear into two parts at the mean temperature of 42, c 
190 days of warm and 175 days of cold weather; the mean temperature crow, 
that line on an average of ten years on the 1st day of May and oth ay o . 1 
vember. . 
If we divide the year into four seasons, and assume winter to continue - ^ 
daily mean is below 32°, spring and autumn to last while the daily me 
below and above the annual mean, or from 32° to 52°, and call 
the daily mean is above 52°, we shall then have the average length oi in 
follows:— . . 
Spring 32° to 52° from 27th March to 31st May. days ‘ 
Summer all above 52° from 1st June to 24 th Sept.1 * " 
Autumn 32° to 52° from 25th Sept, to 26 th Nov....... J>3 " 
Winter all below 32° from 27th Nov. to 26th March...12^ •• 
366 
uantitf 
< 
The mean temperature has varied during ten years only 3J o ^ ^ 0 f or „ 
certainly very inconsiderable when we compare by sensation tn«- ff bok 
hour of the day with another, yet capable, when added or subtiac however, tw 
year, of producing a decided difference in the seasons. We nius n . sunirr .;j 
hastily connect with a low mcun the idea of a cold winter, or tna gCa jont' f 
With a high one. 'lhe heat is added or taken away sometimes throogboot 
quarter of a year, sometimes in another ; and again occasionally a ^ 0 f puH 
the year, as will be more distinctly seen by an examination ot pfr itoi« 
temperature^; or it may be caused bv the difference between the • e0 ffurth‘ f 
of day and night, which I consider an important deviation, and dese 
inquiry, as it affects vegetation. . „ „„ mn , e nced at 
lhe registry of the weather at these mines was originally ci ners so ttej 
request of Admiral Owen, and accordingly published in the Ph«J w . ind , wi* 
he might compare our weather, and more particularly the course m lb* 
tlie register kept by the surveying party on board H.M. steamer _ #t 
Bay of I'undy ; it was afterwards forwarded to the Smithsonian 0 ther p art ‘ 1 
logton to be incorporated along with the numerous registers kept ' of yean- 
the continent of North America ; and having now been kept *p*" . tbc , ' cfn}(3 
it is hoped that the following tables and summary of some facts 
may be of interest to the friends of meteorology. . n e London' 'f 
It is proper here tu acknowledge that Howard's ‘Chniat comp**’ - 
suggested the plan of the greatest part of the work ; -corded by* 1 
climatic phenomena on the east side of North America with those r . Uw , n it 
on the opposite side of the Atlantic or on the west coast of Europe, 
been 
pared’ 
chlef inducement for doing so. , an rorn par- M 
h JLl 3 A U> be rc S reUecl that the instruments used have not .*1 “ te j to be 
T 8; md therefore corrections have been « tte ®P^ fcy the “fj 
n? f hl n!, h | Q 0mCt,0n , of the ^metrical readings for temperaW^. 1 ^ 
of the Royal Society of London. This barometer, with thermometer 
* Brewster’s formula, 81 3 Cos Lat. _ 
T These Tables are not published in the present Repm 1 - 
