XXXvi* THE METEOROLOGY OF THE PLAINS, &c. 
A thermometer hung up in the sun, and freely exposed to its influence, as well as to that of the air, 
was usually from 5° to 10° higher ; the maximum generally taking place about 12. 
Atmospherical pressure is also very equable ; but the observations have not all been made with a 
stationary instrument, nor all at the same place in the hills. At the top of the range, where the houses 
were first built, the barometer observed in September, October, December, and April, did not differ at 
these various times more than one-tenth of an inch, or from 23°60 to 23:50. Mr. 8S. Boulderson has 
published his observations in another part of the same range, called Caineville, from 15th May to 
21st of November: he has 24158 as the maximum mean of seventeen observations, from Ist to 21st 
Nov., at 10 a.m., while 23°815 is the minimum of twenty-two observations in June, at 4 P.M., giving 
a range of .343 inches. 
The daily periodical fluctuation was observed to be as regular in the hills as in the plains. The maxi- 
mum height to which the barometer rose was always about ten o’clock, and the lowest to which it fell, 
about 4 P.M. 
From the equability of temperature as well as of pressure, we might also expect considerable equa- 
bility of evaporation ; but if it were not for the increased capacity of air for moisture, as well as for 
caloric, in proportion to its rarefaction, the climate would be a very moist one, as, indeed, is the case 
in the rainy season. From my observations, however, it appears that there is always a moderate degree of 
evaporation in the Mussooree climate ; the greatest difference, or 20°, between the dry and moist Bulb 
Thermometer, occurred on the 6th May; on the same day, the difference at Saharunpore was 32° 5’. 
On the 5th April, in the morning, after rain, the difference was 7° 5’, while at Saharunpore, on the 7th, 
also after rain, the difference was only 3° 5’. Even when enveloped in a cloud on the Mussooree range, 
I have found 2° difference between the dry and moist thermometers, and on cloudy days the difference 
varied from 4° to 10°. Also at the conclusion of the rains, that is, on the 29th September, the mean of 
the differences on the Mussooree was observed to be 7° 7’, while at Saharunpore it was only 6° 7’. 
The meteorological phenomena observed in the years 1827 and 1828, have been reduced to a tabular 
form, which will give a good general idea of the nature of the climate, as they nearly correspond with 
those observed in subsequent years; but the peculiarity of seasons, their greater dryness or moisture, 
later accession of the rainy seasons, or the total absence of a snow-storm, in some years, will, of course, 
here, as elsewhere, modify the temperature of particular months. 
Resutts of METEOROLOGICAL OBsERVATIONS at Mussoorer. 
Moss Msnceciae® | creat) Mn ae | Meno mins | nee ed Dee 
° ° ° ° ° 
January + es ce cece cece cc eece ec cces 42-45 515 34-5 43 SaOcke 
Bebtuary. << 050. cscsessecssveccess 45°42 63 27 45 42-97 
March .--. ++. see cece cece cece eeeeee on ee 69 37 53 48-2] 
April 25 ecsccccecescsecs pea emuuees 59-83 77 4] 59 46-2 
May --..eereesecercecresacceee eee 66-01 73 4] 59 +6:18 
June er ee ee ee ee ee ee 67:12 74 61 67°5 +1-11 
GULY so ca ceudup sees caer soee cee oe th 67°35 71 63 7°5 —(-23 
August oie ee Te ee ee ee 66°43. 69 63 66 0-92 
September aes ee ae eer ee eee ee te on 64-04 69°5 57 63:25 9-39 
October ee a eae | 57°25 66°5 48. 57°25 wa G79 
November See ae ee ee ee 50. 57 48 5295 7.08 
December ...-sseeserese cree ee eees 45 55 99 42 a 
~ Mean T atu oc ; 
, —. of the Year 57-04 6b f Mean ri agg — 
l Maxima and Minima. 
