21
the air, subject to two forces at an angle between them, follows tlie resultant and seems to diverge, while at othertimes of the year—in October, for instance—the air will rush straight in the direction of the center of a distanttyphoon.
We would advise those who could find the leisure to study Father Algud’s instrument, reading again in quiet,far from the turmoil of the storm, the report of Capt. Geo. Payne, of the steamship Laisang, who bore the bruntof the cyclone in open sea. We are confident that this study will he fruitful and lead to satisfactory results.
Practical application of the barocyclonometer.—In order to illustrate the application of thepreceding rules we give a few instances taken from actual observations. The calculations are madewithout corrections for oscillation except in cases in which the difference of the two values of D 2exceeds five units. In every instance, however, the value y, resulting from calculation with correc-tions applied, is given in brackets.
(1) (a) During tire typhoon of October 12 and 13, 1897, tire famous “Typhoon of Samar andLeyte, ’ ’ 1 the observations at Capiz, on the Island of Panay, were as follows :
October 12, 7.30 p.m.: Barometer 739.0 millimeters ; wind, W. ]
October 12, 8.05 p.m.: Barometer 738.0 millimeters; wind, SW. j j0ne
Capizis within zone 11°—-17° , October in Group II; lienee, P— 755.ing to formula,
755—738 100
755 — 739 ~~ x ‘'
[i/ =94]
Hence we have, accord-
Tlie resulting positions of the needles are given on Plate XLI; and from that follows a directionof the track toward west by north.
(6) During the same typhoon the observations at Manila were :
Hence,
October 13, G a. m.: Barometer, 752.38; wind, NE. |October 13, 11 a. m.: Barometer, 753.25; wind, E. j J ° ne
755 — 753.25 ^.100 .755—752.38 :r '
C?y = 145 ]
Plate XLI shows the positions of the needles; the direction of the track is west-northwest bynorth.
(2) During the typhoon of September 16-17, 1894, the observations at Manila (P=755) onthe 16th were:
September 16, 1 p.m.: Barometer, 749.84; lowest clouds, WNW.September 16, 6 p.m.: Barometer, 746.85; lowest clouds, W.
According to formula,
755—746.85 100
755—749.84 x ''
[y — 64]
Zone B-C.
Plate XLII shows the disposition of the different needles; direction of motion of the center,west by north.
(3) During the “ Gravina Typhoon ” of May 13, 1895, 2 at San Isidro, Province of Nueva Ecija,the observations were as follows:
May 13, 10.00 a.m.: Barometer, 749.76; wind, SE. | ^ ^
May 13, 10.30 a.m.: Barometer, 748.00; wind, S. i
The formula, reads:
755 — 748,00 100 _
755—749.76 x ’’’
[y =so]
The direction of the track as shown by Plate XLII was northeast by north.
'See “El Baguio de Samar y Leyte,” Manila, 1898.2 “Baguio de Gravina,” Manila, 1895.