346 W. Ferrel—Meteorological effects wpon the Tides. 
reduction to mean sea-level, we get 30°016 in. for the mean 
height of the barometer at the mean sea-level in Boston harbor. 
The last column in the table shows that there is a very small 
term with an annual argument and a coefficient of about 0°05 1n., 
making the barometric pressure a minimum about May and a 
maximum about November. The number of observtions was 
not sufficient to eliminate the accidental irregularities sufli- 
ciently to determine this small annual inequality very accu- 
rately, but it is evidently too small to account for much of the 
observed annual inequality in the mean sea-level. fc 
The following table of results is obtained from classifyimg 
the observations of the wind according to their directions, for 
each of the four seasons and for the whole year. 
Season. | N. | N.E. E. S.E. Ss. | S.W. Ww. N.W. 
obs.|s.F.|obs.|8.F.|Obs, 8.F.|Obs|8.F./obs.|8.F.|Obs.| 8.F. |Obs.| 8.F. |Obs.|S.F. 
Winter 92/153} 51| 75| 22| 37| 23] 36] 36) 68|189| 288/221) 378/193)/337 
Spring 68/117|120/183/106'137| 45| 63) 57/109|183| 293 181, 323/113/210 
Summer 34| 52| 85/149/101'143| 37| 61) 50, 67\269| 416,150, 238 104/17 
Autumn 60| 97] 73/129] 51] 82] 31/ 48 43) 751188) 309|167| 275/156/264 
Whole year |254'419/329'536 280 39913291208] 86 319|829|1306/719 1214 5661987 
The number of observations denotes, also, the relative fre- 
quency of the winds from the different points of the horizon. 
It is seen that the predominating winds are from W. and 5.W. 
during all seasons of the year. The numbers headed S. F. are 
the sums of the numbers in the observations denoting the forces 
of the wind. There is some uncertainty with regard to the 
scale used by Professor Bond in denoting the forces, but 1t 18 
supposed to be the scale from 0 to 6, in which 0 denotes calm, 
aud 6 a velocity of 85 miles per hour, the numbers represent 
ing the forces being nearly proportional to the velocities. At 
any rate the sums of the forces above may be regarded as repre- 
senting the relative sums of the distances passed over within 
the limits of the errors of such observations. With a table of 
latitude and departure, therefore, we readily determine the rela- 
tive distances over and the directions, for each season of 
the year and for the whole year. We thus get the following 
table of directions from which the wind blows and the relative 
distances traveled. 
Winter N. 78° W. 726 
Spring N. 85 W. 3886 
Summer Sue. W. 883 
Autumn N. 84 W. 498 
Whole year ON. 87 W. 1920 
It is seen that during the winter the wind blows froma er 
12° N. of W., but in the summer from a point 19° S. 0 
