TRANSACTIONS OF THE SECTIONS. 39 
supplied with the sinews of war. The £3000, which is the very utmost we expend 
annually on telegraphy, including salaries, rent, and every item, is but small com- 
peed with the £50,000, entirely exclusive of salaries, with which the chief Signal 
ce of the United States is so munificently endowed. 
On the Meteorology at Banbridge for ten Years, and Rainfall of Ulster. 
By Joun Suyru, Jun., A.M. 
Banbridge lies in the valley of the Bann, 20 miles from its source, lat. 54° 23'N., 
long. 6° 18’ W., height above sea-level 200 feet. Meteorological observations have 
been carried on since 1861; tables of the results of these and diagrams of the ther- 
mometer-stand and rain-gauge were exhibited. The mean pressure of the atmo- 
sphere for ten years.is 0'133 less than that of Greenwich for 32 years. June has the 
highest mean monthly pressure and January the least. The year 1870 shows the 
highest mean annual pressure, and 1872 the least. The mean temperature of the 
air is 48° F., or 1°-2 below that of Greenwich for 15 years. July has the highest 
mean monthly temperature, viz. 59°-2, or 2°°5 below that of Greenwich. January 
has the lowest, 38°-4, or 0:3 higher than Greenwich ; February is 2° higher. The 
winters are therefore warmer, and the summers cooler than at Greenwich. The 
highest reading of the thermometer was 88° F, on August 4th, 1868, the lowest 11° 
on January 8rd, 1867. The mean humidity is 82 per cent. of complete saturation, 
being 0-4 drier than Greenwich. June is the driest, and January the dampest month ; 
February and March are fergeeye: 2 and 3 per cent. drier at Greenwich, and all the 
other months, except July, November, and Decembef, damper than at Banbridge, 
June and October being 8 percent. The prevailing winds have been from the south, 
and the least frequent from the east. The mean rainfall for the ten years, from 
1862 till the end of 1871, has been 29:2 inches; October shows the greatest rainfall 
and June the least. The rainfall for the year 1872 is the greatest recorded (46:6), 
and for 1864 the least (25°1); the greatest fall in 24 hours was 2:3 inches, in Oc- 
tober 1865. The mean evaporation is 15’6 inches. 
At the Bann Reservoir, lat. 54° 15' N., long. 6°2' W., height above sea 440 ft., the 
mean rainfall was 46 inches, the greatest in 1866 (54°6 inches) and the least in 1869 
(28-9 inches); in the exceptional year 1872 the fall was 61-2 inches; the greatest fall 
in 24 hours was 3°3 inches on October 29th, 1865. The author ceased observing the 
amount of ozone in 1873, as he found always when the same volume of air was exa- 
mined by means of an aspirator, the same amount of ozone was registered, except 
when the test-paper was damped by fog; he was led to expect this from finding the 
intensity of the wind correspond with the intensity of the ozone, as observed in 
Clarke’s cage (this subject is treated more at large by him in a paper read before 
the Association in 1865). 
Rainfall of Ulster—The amount of rainfall at the various stations, as obtained 
from Mr, Symons, were shown on the map exhibited. It was seen that they 
are rather few and unequally distributed, and that the westerly show greater falls 
than the easterly. There is great variety in the physical configuration of Ulster, 
and it is hoped that more observers will be obtained. Our present data are not 
sufficient to enable us to arrive at exact results. 
On the Absorption of the Sun’s Heat-rays by the Vapour of the Atmosphere*. 
By the Rey. Fenwicx W. Srow, M.4., FILS. 
The observations of solar radiation, which are relied on in this paper, are taken 
with “ blackened-bulb thermometers 7x vacuo,’’ suspended 4 feet above the ground, 
the indications of which, when compared with those of the ordinary shade thermo- 
meters, give a measure of the intensity of the solar rays. 
The absorption of the direct solar heat-rays by the vapour of the atmosphere is 
proved in several distinct ways :— 
1, It is found that the elastic force of vapour is less on the ten days in each 
month on which radiation is most powerful than on an average of the whole month, 
* Printed i extenso in the ‘Journal of the Meteorological Sovicty’ for 1874. 
