18 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



latitucJe 10° N. tbey occur a little more frequently tlian ouee a year. From latitude 10° N. to lati- 

 tude 15° N. tbere occur on an average nine "ales annually ; and as we advance northward the fre- 

 quency of gales iucreases with the latitude up to latitude (W° X. 



27. On Maury's storm chart for the eastern half of the North Pacific Oci-an among 17,854 

 observations between the equator and 5° N. latitude, 35 gales are reported ; and between 5° aud 10° 

 N. latitude among 9,352 observations, 33 gales are reported. These observations indicate that in the 

 low latitudes of the Pacific Ocean gales are somewhat more frequent than over the Atlantic Ocean. 

 It appears evident that in both oceans, within 6° of the equator, gales are of extremely rare occur- 

 rence, and wheu they do occur the depression of the barometer is small, and the cyclonic character 

 of the winds is indistinctly marked. North of the parallel of 6° the cyclonic character of the winds 

 becomes more distinct, and areas of low pressure can be identified iu their progress from day to day. 



28. The tropical cyclones which have been found to pursue a westerly course are limited to 

 two districts: 1. The Atlantic Ocean, aud chiefiy its western part near the West India Islands. 

 2. Thei'egion south of the continent of Asia. Tropical cyclones have never been observed iu any 

 l)arl of the Pacific Ocean, with the exception of its western portion near the continent of Asia aud 

 the neighboring islands. I have made a careful study of the cyclones of each of these localities. 

 Table III exhibits some of the particulars resi>ecting each of the cyclones originating near the 



Table III. — Course of cyclonen originating near the West India Islands. 



No. 



Date. 



1 1780, 



2 ! 1780, 

 1H04, 

 1821, 

 1827, 

 lc3ll, 

 1830, 

 1830, 

 1831, 



10 1831. 

 U 1831, 

 la ; 183.^,, 



13 I 1835, 



14 1837, 



15 I 1837, 



16 ; 1837, 



17 I 1837, 

 1837, 

 1839, 

 1842, 

 1842, 

 1844, 

 1840, 

 1S46, 

 1847, 

 1848, 

 1848, 

 1850, 

 1851, 

 1853, 

 le53, 

 1853, 

 1866, 

 1867, 



35 1871, 



36 1871, 



37 1873, 



38 i 1873, 

 1»73, 

 1874, 

 1875, 



Oct. 3 

 Oct. 12 i 

 Se)>t. 3 

 .Sept. 1 

 Aujr. 17 

 Aug. 12 , 

 Aug. 22 

 Sept. 29 

 Jau. 13 

 JUUI.-23 

 Aug. 10 

 Aug. 12 

 Sept. 3 

 July 26 

 Aug. 2 

 Aug. 12 

 Aug. 24 

 Sept. 27 

 Sept. 12 

 Aug. 30 

 Oct. 2 

 Oct. 4 

 Sept. 11 



Oct 

 Oct. 

 Aug 

 Aug, 

 Sept 

 Aug. 16 

 Aug. 30 

 Sept. 26 

 Sept. 29 

 Oct. 1 

 Oct. 29 

 Juue 1 

 Sept. 5 

 Aug. 18 

 Aug. 20 

 Oct. 6 

 Feb. 7 

 Sept; 14 



16.5° 

 11.8 



15.7 

 21.7 

 14.8 

 17.3 

 22. 3 

 20.2 

 30.0 

 10.3 

 12.3 

 16.3 

 12.4 

 11.0 

 17. 3 

 17.6 

 32. 7 

 15.7 

 18.5 

 21.6 

 20.0 

 18.6 

 13.8 

 14.2 

 12.8 

 15.0 

 15.0 

 16.0 

 13.5 

 12.5 

 28.8 

 13.9 

 19. 

 18. . 

 23.5 



Course whilei a g 



moving 'Z-.-^ 



westward. .- J? 



o ~- 



W. 31^' N. 

 W.30 N. 

 W.27 N. 

 W.29 N. 

 W.23.5 N. 

 W.27 N. 

 VV. 33.5 N. 



w!V4..'i'N] 

 W.25.5 N. 

 W. 17 N. 

 VV.38 N. 

 \V.29 N. 

 W. 31.5 N. 

 W.20 X. 



\V.'24 N." 



W. 26 N. 



W. 1 N. 



17.8 

 20.4 

 35.0 

 12.9 







iC'ourse while 



moving 

 I eastward. 



23.3 

 31. 2 

 31.2 

 30.0 



23. 8 31. 4 



18.7 

 26.4 



20.4 

 16.6 



117.8 



30.3; 



30. 4| 

 30. 0! 



... I 

 30.7 



W. 62 N. 

 W.60 N. 

 W. 11.5 S. 

 W.28.5N. 

 W.22 N. 



W.5 N. 



W. 15 N. 

 W. 12.5 N. 



\V. 9 N. 

 \V.15 N. 



W.2 S. 

 W. 14 N. 



8.3 



io.o 



10.3 

 21. 2 



E. ai.fto N. 

 ■E. 39.5 N. 



E. 46 N. 

 E.55 N. 

 E.43 N. 

 E.37 N. 

 E.40 N. 

 E.43 N. 

 E. 53.5 N. 



30.0 



31.7 



26.2 

 32. 2 



E.24.5 N. 



E.47 N. 



E. 17.5 N. 



.... E. IbN. 



.... E.54N. 



29.2 li;.47 N. 



30.0 E. 60.5 N. 



27.4 

 29. 



E.22 N. 

 E.24 N. 



17.5 27.3, E.34 N. 

 25. 3 31. 7 1 E.24.5 N. 

 -.29.2 E.27 N. 



15.0,26.4' 



15..-,!....;, 

 12. 3,31. 5i 



E.25 N. 



20. 

 25. U 

 21. 3 

 24.0 

 23.0 



\V.32 N. 

 W.51 N. 

 W.28 N. 



W. 22 N. 



112. 3 33. Oi 



!l0.5l34.3 



9.5I24.3 



1 . . . . |26. 5' 

 125.1,28.5 



E. 45 N. 

 E. 38 N. 

 E.37 N. 

 E,41 N. 

 E.45 N. 

 E.45 N. 

 E.24 N. 



f^-^ 

 ^ ^ 



17. 2 

 18.1 

 25. L) 



Kaiu-fall 



Hard rain . . . 

 Hard rai n . . . 

 V. banl raiu 

 Hard rain .. 



10.0 Hard raiu ... 

 16. 3 V. hard raiu. 



16.01 Raiu 



29.6 



16. 6 Snow 



Hard rain . . 



Rain 



Hard rain . .. 



V. hard rain. 



Hard rain . . . 



Rain 



Hani niiu . . . 

 13. 4' Hard raiu . ,. 

 . . . . i Hard rain . . . 



Rain 



Hard lain . .. 



Hard raiu .. 



Hard raiu . . . 



Raiu 



Raiu 



Investiga- 

 tors. 



17 



10.6 

 30.4 



14. 3| 

 23. 5 



18.7 

 28.4 



30. 



23. 



Hard rain 



Raiu 



Raiu 



V. hard raiu 

 V. hard r;iiu. 

 Hard rai u . . . 



Raiu 



V. bard rain. 

 Rain 



15.0; Raiu . 

 ,18.4 Raiu , 



16.4 

 30.1 

 23. 5 

 29.6 Hard rain 



V. liard rain 

 Hard niin . . 

 Raiu 



I 



Eeid 



Reid .... 



Redfield. 



Redfield. 

 j Redfield. 

 I Redfield. 



Redfield. 



Redfield. 

 [ Redfield. 



Redfield. 



Redfield. 



Redfield. 

 I Reid .... 



Reid 



I Reid 



Reid .... 



Reid .... 



Reid.... 



Reid ... 



Redfield. 



Redfield . 



Redfield . 



Redfield. 



Redfield. 



Reid 



Reid 



Maury .. 



Redfield. 



Redfield . 



Redfield - 



Redfield. 



Redfield. 



Buchan . 



Eastman 



Sig. Serv 



Sig. Serv 



Sig. Serv 



Toj'ubee 



Sig. Serv 



Sig. Serv 



Sig. Serv 



Where recorded. 



Law of Storms, p. 273. 

 Law of Storms, p. 273. 

 Jo. Sci.,v.20,p. 17. 

 Jo. Sci., V.20, p. 17. 

 Jo. Sci.,v.31,p. 123. 

 Jo. Sci., v.20, p. 34. 

 Jo. Sci., v.20, p. 39. 

 Jo. Sci., v.20, p. 42. 

 U. S. Naval Mag, 1836. 

 Jo. Sci., V. 31, p. 123. 

 Jo. Sci., V. 21, p. 192. 

 Jo. Sci., V. 31, p. 124. 

 Law of Storms, p. 36. 

 Law of Storms, p. 48. 

 Law of Storms, p. 48. 

 Law of Storms, p. 69. 

 Law of Storms, p. 109. 

 Progress, p. 13. 

 Progress, p. 39. 

 Jo. Sci., V. l,p.2. 

 Jo. Sci., V. 1, p. 153. 

 Jo. Sci., V. 2, p. 312. 

 Jo. Sci., V. 18, chart. 

 Jo. Sci., V. 18, chart. 

 Progress, chart. 

 Progress, p. 337. 

 Phys. Geog.,p.60. 

 Jo. Sci., V. 18, p. 176. 

 Jo. Sci., V. 18, chart. 

 Jo. Sci., V. 18, p. 1. 

 Jo. Sci., V. 18, p. 180. 

 Jo. Sci., V. 18, p. 178. 

 Haudy Book, p. 151. 

 Pamphlet. 

 Report lf)72, p. 282. 

 Report 1874, map. 

 Report 1873, p. 1029. 

 Jo. Met. Soc, V. 2, p. 15. 

 Monthly Map, 1873. 

 Report 18T4, map. 

 Monthly Map, 1875. 



