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China Sea by myself; for without a knowledge of the average tracks the problem of the management of a vessel becomes much more intricate for the seaman; since it is upon the track of the Storm (as upon that of a pirate or enemy) that his manœuvres must depend, and this he must know or know how to calculate. Hence the importance of this chart in a nautical point of view.

There is one more relation in which I venture to present it, and that is the following. If we produce by the eye or a ruler the various tracks of the Storms backwards to the Eastward on the same line we shall find them all tending as it were, to some focus of volcanic action now in activity. Beginning from the South, the first set appear to come from some of the numerous Sumatran Volcanoes or of the Volcanic islands which fringe its coasts. The next set, and these are the most remarkable, will mostly be found to arise about Barren Island, which is a Volcano always in activity, and to run towards points between the West and N. N. W., while a third, the Dacca and Kyook Phyoo hurricanes seem traceable from the volcanic centres of Cheduba (or Chittagong.)

It is difficult to say that these coincidences are not more than accidental, but I shall best explain my general views on the subject by the following, copied from my forth-coming work, p. 19, par. 33 :—

"Other suggestions have been thrown out and instances adduced by different writers as to the possibility of volcanoes, and even fires, originating violent circular motions of the atmosphere, and that volcanic eruptions are often accompanied by violent storms and heavy falls of rain, there is no doubt. I have myself pointed out, though my published Researches have hitherto been confined like those of Redfield and Reid to the effects, as the sure eventual index to guide us backward to the causes of Storms, that in the China Sea and Bay of Bengal* there is much to countenance the idea that Storms in some parts of the world may originate at great volcanic centres, and I am inclined to believe also that their tracks are partly over the great internal chasms of our globe, by which perhaps the volcanic centres and bands communicate with each other. If we produce at both ends the line of the track of the great Cuba hurricane of 1844, we shall find that it extends from the great and highly active volcano of Cosseguina on the Pacific shore of central America to Hecla in Iceland! and in 1821 the breaking out of the great volcano of Eyafjeld Yokul in Iceland, which had been quiet since 1612, was followed all over Europe by dreadful storms of wind, hail and rain. In Iceland the * Sixth Memoir, Storms of the China Sea, Journal Asiatic Society, Vol. XI. p. 717.

80

References

in

The Roman numerals

refer to those numbers of mu

the Journal of the Asiatic Society of Bengal in which

of this part of the world are investigated

The Italis letters refer to Storms for which I have.

which are yet unpublished

a Ongele Hurricane...

oct " 1800

i London

b. HMS Centurion,

Dec 1803

J Duke of York

THE LIBRARY
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Barometer fell from the day before the eruption till the twenty-sixth day after.* Mr. Espy quotes several other cases, and Humboldt for South America, to show that nothing is better established than the fact of the connection of volcanoes with rains and storms. Purdy (Atlantic Memoir) also alludes to the supposed focus of sub-marine volcanic action on the Equator, in that sea, as the spot to which the southern extremes of the West Indian hurricane tracks would tend, if continued. If I advert to these speculations it is with the hope of drawing the attention of intelligent mariners to them."

* Espy, p. 67, 68, not correctly printed.

[blocks in formation]

Meteorological Register kept at the Surveyor General's Office, Calcutta, for the Month of July, 1847.

Maximum Pressure observed at 9h 50m.
Temperature. Wind.

[blocks in formation]

1 In.29.554

84.8 84.0 80.8 S. E.

.462 89.0 86.0 81.5 S.

Cloudy.

Cumulo strati.

.471, 87.3 86.1 82.0 S.

Cloudy.

4S

.556 80.5 80.9 77.8 S.

Cloudy.

11S

14

.651 82.5 81.5 77.0 E.
.662 89.0 87.8 80.2 S.
.587 89.0 88.0 81.0 S.
.523 89.0 87.5 81.0 S. W.
.517 85.0 85.6 82.0 S.
.485 85.8 85.0 80.4 S. W.
.485 88.5 87.0 82.0 N. E.
.517 87.0 87.0 82.0 N. E.
.485 81.0 81.4 80.0 S. W.
.519 87.0 85.8 80.8 S.

Cloudy.

Cumulo strati.

In.29.436 88.0 85.0 80.0 S. E.
.406 86.0 80.5 79.4 S. E.
.395 87.0 86.0 81.0 S.

.499 83.0 83.0 78.4

.572 88.5 86.5 80.0 S. .555 94.0 91.5 81.0

[blocks in formation]

Cumulo strati.

.465 91.4 90.6 82.0 S.

Cirro strati.

94.2

Cumuli.

.400 94.5 92.0 83.2 S. W.

Very cloudy.

95.9

0.20 0.27

Cloudy.

.421 89.5 88.5 82.6 S.

Cloudy.

89.6

0.68 0.74

Cloudy.

.430 78.0 79.0 77.3 N.

Drizzly.

89.0

2.99 3.09

Cloudy.

.400 91.7 89.2 82.2 S. E.

Cloudy.

99.2

0.22 0.29

Cloudy Cirro-Cumuli.

.417 89.5 88.0 82.3 N. E.

Cloudy.

91.4

0.78 0.87

[blocks in formation]

.420 87.0 86.9 82.0 W.
.421 89.8 88.2 81.4 S.
.392 86.5 86.1 82.8 S. E.
.445 86.8 86.0 80.8 S.
.570 86.0 86.0 79.0 S.

.606 90.0 88.5 80.2 S.
.577 87.0 86.8 80.3 S.
.585 84.3 84.4 79.9 S.
.563 89.9 89.0 81.0 S.
.466 95.7 89.4 82.1 S.
.493 88.0 86.9 82.0 S.
.534, 81.5 81.8 79.0 S. E.
.534 87.0 85.0 80.5 S. E.
.551 87.0 83.7 79.0 S. E.
.582 91.0 89.2 81.5 S. E.
.623 89.0 87.9 81.0 S. E.
.626 91.0 89.5 81.8 S.
.593 90.5 90.2 81.3 S.

[blocks in formation]

Cloudy.

87.2

0.21 0.27

Cumulo strati.

91.4

0.05 0.06

[blocks in formation]

Cloudy.

89.4

0.18 0.23

87.9

0.24 0.34

Cumulo strati.

[blocks in formation]

29.500 88.3 86.9 80.8)

91.0

14.14 15.69

no 201

86.8) 85.8 81.9

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