1802.) 
for each of thefe divifions. In his tables, 
the three firft columns contain the great- 
eft, leaft, and mean heights of the baro- 
meter, for each divifion of the month ; 
and the fourth column gives the tempera- 
ture of the air in the room where the ba- 
rometer is kept ; the fifth and fixth co- 
lumns thew the greateft height of the ther- 
mometer in the air that was odferved dur- 
ing the ten days to which the numbers 
“refer; the next three give the mean heights 
as obferved at three different times every 
day, viz. at 3 in the morning, 10 in the 
evening, and, as nearly as poflible, when 
the day is warmeft, that is, fom-time be- 
tween mid-day and three in the after- 
noon. ‘The mean of all thefe is taken for 
the mean temperature of the day ; which 
being computed for each day, the mean of 
all thefe mean temperatures is fet down as 
a medium temperature of the air for every 
one of the thirty-fix divifions of the year. 
The mean of the three divifions of every 
month is given inthe next column, under 
the title ot The Mean Temperature of the 
Month. 
‘Ic is prefumed (Mr. Playfair fays) 
that the mean temperatures, which are 
points moft difficult to be afcertained, are 
given with tolerable exattne(ls, as they are 
deduced from three obfervations made 
every day, of which the firft, that at 8 in 
the morning, is itfelf not far from the me- 
dium temperature of the whole day ;* and 
the other two are as near as circumftances 
will allow to the two extremes of great- 
eft heat and cold.”’ 
At Edinburgh, the mean temperature 
of the year 1797 was 48°.04 ; of the year 
1798 it was 49.28 ; and of the year 1799 
it was only 46.13. 
Mr. Playfair’s remarks on the weather 
of each year are judicious and interefting : 
we fhall quote part of what he fays re{pect- 
ing the year 1799. 
«¢ Tine mean temperature of the whole 
year is 46°.13, more than 1°.8 below the 
ufual mean (43°). But the mean tempe- 
rature of the feaion of vegetation, com- 
* By a gentleman who has been in the 
habit of attending to this fubje& many years 
in the neighbourhood of London, the mean 
temperature is, I believe, reckoned rather 
about nine in the morning thar eight. And 
it may not be improper to notice, that ten in 
evening will not, in general, give the greateft 
degree of cold ; accuracy, in the climate of 
the metropolis, requires the greateft cold to 
be taken commonly, for the ruleis by no 
means univerfal, in the morning, fome lit- 
tle time before fun-rife, 
z 
Proceedings of Learned Societies. 
429 
puted from the zoth of March to the zoth 
of Oftober, isno more than 51°.27, almott 
5° below that of the preceding year. ‘This 
deficiency of temperature may appear at 
firft fight hardly adequate to that defici- 
ency in the crop which is afcribed to it 5 
but it fhould be confidered that vegetation 
fcarcely proceeds at all with a tempera~ 
ture under 40°, fo that this may not im- 
properly be regarded as the point of heat 
at which vegetation begins, and the 
boundary, in as much, at leat, as refpets 
agriculture, between fruitfulnefs and He- 
rility. Now, 56° is the mean temperatare 
of a good feafon in this country (Edins- 
burgh), as we know from the inftance of 
179%; and therefore 16° of heat is the 
whole diftance between the mere cermina- 
tion of vegetables, and the fulle4 matu- 
rity they can attain in our climate. Ae 
deficiency of 5%, therefore, which is near- 
ly one-third of the whole 16%, muft ne- 
ceflarily be accompanied with great defi- 
ciency in the maturity of all vegetable pro- 
dudtions. 
**¢ Whether the quantity of the crop may 
be expeéted to be proportional to the ex- 
cefs of the mean temperature of the vege- 
tating-feafon above 40°, or if it beina 
greater or a lefs ratio, may deferve to be 
more accurately confidered. There is, 
however, reafon to think that the varia- 
tions of the crop, at leaft of the corn- 
crop, will be greater than in proportion ta 
the variations of temperature ; for, if the 
mean heat of the vecetating-feafon were to 
fall as much below that of 1799, as the 
heat of 1799 did below that of 1798, it 
would be reduced to 46°, a temperature 
fo low as would certainly prevent the 
ripening of corn altogether.” 
The quantity of rain which fell in Edin- - 
burgh was equal indepth to 25.360 inches 
iN 1797; ‘0 23.855 in 1798, and to 
25-874 in 1799. Mr. Piaytair has not 
mentioned at what height his rain-guaze 
fiands, which is very material to be 
known. 
The Royal Academy of Berlin, among 
other prizes, has offered a triple one, for 
the beft Differtation on the Obliquity of 
the Ecliptic. Papers on this fubj-c& to 
be received till the 1rft of May, 1806. 
Another prize is offered for the bef an- 
fwer to the following queftion :—** Has 
Eleétricity any Influence on Matters ina 
State of Fermentation; and what Advan- 
tage can be derived from calling forth 
this Matter, in order to improve the Art 
of preparing Wine, Beer, Vinegar, and 
Brandy ?”” 
MONTHLY 
