XeVl GENERAL RESULTS OF THE MAKERSTOUN OBSERVATIONS. 
TABLE 90.—Monthly Means of the Maximum Pressure of the Wind within 10™ at the Observation 
Hours for the Years 1843-6. 
March. | April. | May. 
199. Annual Variation of the Approvimate Mean Pressures of the Wind.—From the means of 4 years’ 
observations, the wind blew with the greatest mean force in January, and with the least mean force in Septem- 
ber. The mean pressure, however, varies little for the six months October to March, while the sun is south 
of the equator ; it is nearly constant for the three months, April, May, and June, diminishing gradually from 
June to September. September is the month of least pressure in each year, excepting 1844; the month of 
maximum pressure is more variable, January in 1843, November in 1844, December in 1845, and Mareh in 
1846. 
TABLE 91.—Variations of the Pressure of the Wind with reference to the Moon’s Age and Declina- 
tion for the Years 1843-6. 
After 
Moon 
farthest 
North. 
ay atau 
27— 1) 
= i | 
6— 8 | 
9—12 | 
13—15 | 
16—19 | 
20—22 | 
23—26 
200. Approximate Mean Pressure of Wind with Reference to the Moon’s Age—The mean result from the 
first portion of Table 91 shews, that the pressure of the wind was a maximum at conjunction and a minimum near 
opposition. The result for each year shews a well-marked minimum near opposition, and a maximum near 
conjunction. It has already been noticed (No. 194), that the diurnal range of the atmospheric pressure obeys 
a similar law; that is to say, for this argument, the diurnal oscillation of the statical pressure of the atmosphere 
is a maximum when its dynamical pressure is a maximum. 
201. Approwimate Mean Pressure of the Wind with Reference to the Moon’s Declination.—From the last 
column of Table 91, the mean result of 4 years’ observations, it appears that the pressure of the wind is a maximum 
when the moon is farthest north. This result is shewn with some distinctness in each year, excepting in 1843, 
for which the maximum occurs when the moon is farthest south ; there is, however, the appearance of a maxi- 
mum near the time of the moon's farthest southerly position in the years 1845 and 1846 ; and, indeed, in the 
mean for the 4 years ; it is probable therefore that the minimum pressure of the wind occurs when the moon 
is near the equator. The same relation, between the diurnal oscillation of the statical pressure of the atmos- 
phere and its dynamical pressure, holds as in No, 200. 
