69 
in the southern hemisphere, a sailor would assume that the centre ot 
the cyclone was in the N.E., and accordingly steer for N.W., so as to 
pass the centre ; but by the new rule he would sail straieke to the 
centre. 
The necessity of a correct knowledge of the laws was shown by 
the fact that in one on February 25th, 1860, this mistake was made, 
and-thirty-one vessels were lost near Mauritius, amounting in value to 
£134,000. In cyclones of the elliptical form the wind curved in towards 
the centre, and they were therefore called “incurving cyclones.” It 
was not yet known whether any incurving cyclones were ever felt in the 
northern hemisphere, or, indeed, outside the Indian Ocean ; but it was 
thought that the Atlantic hurricane of August 20 to 24, 1873, was of 
that character. 
The velocity and force of the wind were recorded by instruments 
called anemometers. Those for the velocity had been invented 
by Robinson and Whewell, but Robinson’s was most commonly in use. 
The chief pressure anemometer was invented by Osler. 
The relative prevalence of the wind was shown in the following 
table, which gave the average number of days the wind blew from each 
point of the compass in each month, the average being for six years, 
1868 to 1873 inclusive. The observations were made from the vane of 
St. Nicholas Church, Brighton. 
The Uckfield annual totals were given for comparison. 
Number of days wind blew from 
N. NE. E. SE. S.\° SW. W. NW. Calm. 
JANA. 25 si ssccsel 3 5 3 2 4 6 7 eS I 
EDIUATY. ...<.c00003% Sark 2 I aero 6 2 I 
March’. sim:.-... BAG 6 2. 2 3 5 5 2 I 
Borie sss bes. oath SRP w 6 2 SP IAg 5 6 2 PP 
Math aad. sspiabiegc 2 6 2 3 3 6 6 2 I 
NUNC i. a.08 mes adntekine 8 ers I 2 2 8 7 I 3 
MOECAtas sites ca'soguecevcn ) 2 4 I 2 Saati) 6 I 2 
MUP USt Lede 3 3 2 3 2 7 6 2 3 
September ......... 2 4 3 S 2 6 7 2 I 
BIOCEODET «7. seenceeenc0-5 3 2 2 2 4 5 8 4 I 
November............ OO} Se te 2 I 3 5 4 3 i 
December............ 6 5 I I 5 5 6 2 
EROtalic sw usadssads AO Seabee 2h e SO eA re MAL 2, 237s EA. 
Uckfield average, fi 
27 years. 2 OO ase ee ey go G8. Set Mee 
From this it would be seen that both at Brighton and Uckfield the 
