Page:Popular Science Monthly Volume 22.djvu/647

This page has been proofread, but needs to be validated.
629
ICEBERGS AND FOG IN THE NORTH ATLANTIC.

cause of the increase in the traffic, and in the number of passengers transported.

Every one who has sailed for any number of passages on the western route via 43° latitude and 50° longitude—the track usually followed in ice-months—must have often experienced the sudden change from a dense fog to fine, clear weather, and sometimes to an almost cloudless sky. This change occurs most frequently to the westward of the Grand Bank, and with the wind to the south of west; the clearing which follows a northerly wind taking place more slowly. This sudden lifting of the fog is nearly always due to a change in the temperature of the surface-water. In sailing from the 43d to the 41st parallel, between the Grand Bank and George's, 1 have occasionally known the fog to clear and shut down again many times during the twenty-four hours; and almost invariably, upon trying the surface-water, found that while the weather continued clear the surface temperature rose to between 55° and 65° Fahr., and, upon the temperature of the water falling below 55° Fahr., the fog again closed in; to be again followed by clearer weather as the ship sailed into warmer water—thus alternating from a dense fog to a clear sky and pleasant weather for hundreds of miles.

In the summer of 1875, during which great quantities of ice were encountered, I began to experiment on running south to clear the fog. Probably the idea originated from my knowledge of the courses taken by the old New York and Liverpool packets, nearly all of which, on leaving Sandy Hook, in the spring and summer months, steered east by south true until they were to the eastward of 70° longitude, and crossed the 50th meridian very rarely to the northward of 43° latitude, and generally in 42° or south of that parallel. In the course of one or two seasons, on comparing our logs of previous years and those of other steamers leaving about the same dates, with our logs on the southerly route, the conviction became irresistible that crossing 50 west to the southward of 41° latitude was the safest course eastward bound. I am fully aware of the many arguments that may be used against this southern route for both east and west bound steamers; among others, the Gulf Stream, the longer distance, the discomfort to passengers in a crowded ship, the excessive heat in the fire room, and probably many others; but, after much attention to the subject, I am convinced that these objections are more than counterbalanced by almost certain immunity from fog and ice, or the assurance that, if the latter is encountered, it will be in clear weather. I have therefore continued crossing the meridians of 50° and 45° farther to the southward every year during the ice-months, until in the present year (1882), after having made ten passages east and west, from March to August inclusive, only one hour and thirty-one minutes of fog has been encountered between Cape Henlopen and Cape Clear on the eastern passages, and that was experienced in 65° west in the month