142 APPENDIX. 



mentioned, gives a diameter to the storm of 388 English miles, at that particu- 

 lar period of its existence. Reduce this diameter 28 miles in order to be 

 •within bounds, and it will then be 360 Eng. miles in breadth. Now, suppose the 

 extreme height of this hurricane from the surface of the earth, to be two such 

 miles, which is probably beyond the reality, and we shall have a whirling 

 mass of atmosphere and cloud, representing a flattened disk, the width of 

 which would be equal to 180 times its own thickness, or, resembling, in diame- 

 ter and thickness, the proportions of an ordinary dinner plate. This immense 

 circle would cover an area of 101,787 square miles, and would be quite flat if 

 the surface of the earth presented a dead level ; but, moving over a rounded 

 or globular form — the segment of a sphere — the under side of the hurricane 

 would necessarily be concave, and the upper surface convex, to correspond. 



In this form, I conceive, did the hurricane of 1839 advance from the 

 Bermudas towards the N. and N.E., revolving upon its centre (which centre 

 passed immediately over those islands) from right to left, if viewed from a stand- 

 ing point in the centre ; with what velocity we know not, but if estimated at 

 five times the rate of direct progress, it would give 120 miles per hour. 

 During the prevalence of this hurricane in Prince Edward Island, the wind 

 veered from N.E. to S.E. S.W. and N.W., where it terminated sometime 

 before daybreak on the 14th. A few old buildings were levelled to the ground, 

 and sundry trees of thirty years growth blown down, but, with these excep- 

 tions, little material damage was sustained. The outer margin of the gale 

 extended to Bay Chaleur, where H.M.S. "Andromache" was then riding at 

 anchor. In that locality, however, it was not severe. 



In Keith Johnston's Physical Geography for Schools, it is stated that the 

 West India hurricanes commence near the Leeward Islands, travel to the 

 W.N'.'W".,and then round the shores of the Gulf of Mexico, following the Gulf 

 Stream, and are lost between the Bermudas and Halifax. Other writers 

 terminate such storms south of the Island of St. Pierre, Newfoundland. 



The hurricane of September 11th, 1839, took a more easterly course, and 

 was certainly not lost in the longitude of Bermuda, or St. Pierre, Miquelon. 



It is a remarkable fact that in the ten degrees of latitude north of the equa- 

 tor, in the Atlantic, hurricanes are unknown, and that the same exemption 

 extends to every part of the South Atlantic. It is, then, between the 10th and 

 20th parallels of north latitude that we must look for the commencement of 

 these storms, so ably described by Mr. Redfield and the late Sir William Reid. 



The greater number of the so-called West India hurricanes pass to the 

 north, between the Bermudas and the shores of the United States, sometimes 

 in close proximity with the former, and on other occasions sweeping over the 

 seaboard of those States. The hurricane of September 11th, 1839, passed, 

 however, directly over the Bermudas, eastward of the usual track, and we 

 know that it was not lost in the longitude of Halifax, N.S., but continued its 

 course into the Atlantic with fearful violence. 



A revolving tropical tempest of this enormous extent, high rate of speed, 

 and power, with a wide ocean before it, free from islands, mountains, and other 

 physical obstructions, must, under the circumstances, continue its onward and 



