OF FREQUENCY OF THE BAROMETRIC HEIGHT AT DIVERS STATIONS. 44.9 
from this Table. The results will, of course, only be correct to a corresponding 
degree of accuracy. The positive sign is given to 
Table YII.— Skewness in Variability and Range. Unit, one inch. 
Station. 
G- 
G- 
+ 
to 
< 7 . 
St. Leonards. 
0-191 
0-225 
0-416 
0-318 
Southampton. 
0-187 
0-233 
0-4-20 
0-3-29 
Bahbacombe. 
0-187 
0-234 
0-421 
0-330 
Carmarthen. 
0-197 
0-246 
0-443 
0-347 
Churchstoke. 
0-202 
0-252 
0-454 
0-356 
Llandudno. 
0-213 
0-256 
0-469 
0-359 
Parsonstown. ’ . 
0203 
0-260 
0-463 
0-363 
Markree Castle. 
0-219 
0-283 
0-502 
0-392 
Armagh. 
0-204 
0-270 
0-474 
0-370 
Londondei’rj. 
0-217 
0-273 
0-490 
0-384 
Stonyhurst. 
0-207 
0-248 
0-455 
0-350 
Scaleby. 
0-210 
0-268 
0-478 
0-373 
Glasgow. 
0-214 
0-279 
0-493 
0-379 
Laudale. 
0-210 
0-282 
0-492 
0-388 
Dunrobin Castle. 
0-212 
0-274 
0-486 
0-379 
Dundee. 
0-214 
0-279 
0-493 
0-384 
Scarborough. 
0-203 
0-256 
0-459 
0-360 
Hilling ton. 
0-193 
0-244 
0-437 
0-343 
Geldeston. 
0-191 
0-237 
0-428 
0-334 
Margate. 
0-175 
0-235 
0-410 
0-332 
British Isles. 
0-200 
0-253 
0-453 
0-356 
It will be found that the following empirical formulae give the values of and Cj 
with an accuracy quite as great as that of their determination by interpolation from 
De Forrest’s table :— 
= o-(0-6520 - 0-4728 S^), 
= o- (0-6488 + 0-3343 S^). 
These formulae must, of course, only be ajDplied with caution beyond the British 
Isles, and still less to other problems in skew frequency, when the skewness does 
not fall within the range of barometric skewness considered in this paper. Within 
this range, however, they give remarkably good results. 
The above formulae, or the table, show at once that and are quantities which 
follow the system of generalised isobars, and thus -f Cg and e^, are good measures 
of the range and its skewness. It is, accordingly, these quantities which ought to 
be calculated for the purpose of obtaining an appreciation of the range above and 
below the mode at any station. 
For example ;—At St. Leonards half the frequency of the barometer falls into a 
range of ’416", namely, from 29"'801- to 30"’2I7, he., the mode being 30"-026, from 
30"-026 — to 30''-026 + Further, the relative scattering of the frequency 
above and below the mode is given by the ratio of e-^ : Co or 0*191 : 0-225. At 
Markree Castle, on the other hand, it requires more than half-an-inch to cover half 
the frequency, i.e., from 29"-6825 to 20^^*1845, and the ratio of 0*219 : 0*283 gives 
the relative ranges of half the frequencies above and below the mode. 
The comparatively small amount of labour necessary to determine Sk and cr,— 
VOL. cxc. —a. 3 M 
