MUKKICANES. 267 



in an hour. Pievious to the setting in of the gale, the wind was from South to 

 S.E., but changed to the N.E. at the commencement of the storm, and blew with 

 great fury till evening, and then shifted to the Westward. 



(200.) The Cyclone of August, 1870,* took the following course. The calm centre 

 passed Antigua on August 21, at 6*" 40" a.m. ; St. Kitt's, at 9^ a.m. ; St. Eustatius, 

 at noon ; St. Thomas, at 5*' 15™ p.m. ; Turks Island, August 22, at midnight ; 

 Long Island, August 23, at 5^ 30™ p.m. ; Great Exuma, at 8'' 30™ p.m. ; Nassau, 

 August 24, at 4'' 30'" p.m. ; and reached the vicinity of Key West, about 8"^ p.m., 

 on the same day. 



The rate of progress of this Cyclone, in passing Antigua, was 18 miles per hour. 

 At St. Thomas it slackened to 13| miles per hour. In Florida it was only 8^ mUea 

 per hoiu", and farther North only 5 miles per hour. This diminution in the pro- 

 gressive movement may probably be accounted for by the obstruction to the 

 Cyclone created by the hills in several of the islands over or round which it had 

 to pass. 



With regard to the diameter of the Cyclone, Mr. Jahncke, of St. Thomas, who 

 seems to have studied the whole phenomena most scientifically, estimated what 

 he calls the "inner or furious part," at about 180 or 200 miles; the entire diameter 

 was about 300 miles. Others, however, judging from the track marked on some 

 of the islands by the damage done, estimated the diameter at only 50 or 60 miles. 

 As to the central part, where a comparative calm existed, that of course was 

 formed by the meeting of opposite winds, just as near the Equator a calm region 

 prevails from the same cause. The diameter of this central cyclonic cahn may 

 be estimated ; for if it lasted half an hour at any place passed by the Cyclone, and 

 the Cyclone itself was moving forward at the rate of 18 miles an hoiu", the calm 

 centre must have been about 9 miles in diameter. 



The following shows the barometric depression and direction of wind at St. 

 Thomas :— August 21, noon, 2983, wind N.E. ; 1 p.m., 29-57, N.N.E. ; 2 p.m., 

 29-19, N.N.E. ; 3 p.m., 29-17, North ; 4 p.m., 2885, N.N.W. ; 6 p.m., 28-68, West; 

 5'' 35™ p.m., calm ; 6 p.m., wind S.W. ; 7 p.m., wind S.S.W. The barometer rose 

 gradually after the calm. 



This Cyclone is stated to have been divulen into two poi-tions in passing the high 

 ground (6,000 feet) of Puerto Rico. One part of the Cyclone diverged to the 

 N.N.W., and the other and larger portion proceeded onward W.N.W. The first 

 part of the Cyclone, Mr. Jahncke states, went towards Bermuda, and was encoun- 

 tered by the brig Ada, in lat. 26°, long. 69°. 



(201.) Mr. Keevil, United States Consul at Martinique, gives the following 

 account of the severe Hurricane which occurred there on August 18th, 1891 (see 

 Track No. XIII. on diagram) : — 



Early in the morning the sky presented a very leaden appearance, decidedly 

 threatening, with occasional gusts of variable winds, mostly from E.N.E. The 

 temperature was very oppressive during the entire day. The barometer varied 

 only slightly, but was a little higher than usual until the afternoon, when it com- 

 menced to fall, at first gradually, and then very rapidly. 



It is stated by fishermen, who were in the vicinity of Caraval Eock at 10 a.m., 

 that an immense wave, about 100 feet high, passed from the direction of St. Lucia, 

 closely followed by another smaller one, although the sea in the vicinity was quite 

 calm at the time. 



The storm struck the East side of the island at about 6 p.mv, rushing through 

 the ravines with terrible force, and destroying everything in its path. On the 

 elevated plains the ruin was most complete. One very peculiar feature of the 



♦ Notes on West India Cyclones, by D. Milne Holme, LL.D. "Journal of the Scottish 

 Meteorological Society," 1874. S'ie alsc page 219. 



N. A. 0. 34 • 



