Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2- Appendix): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

APPKXDIX. - 277 No. 46. WlXDS. Much notice has lately been taken of the theory respecting storms ; suggested by Colonel Capper in 1801, discussed by Mr. Redfield in 1831, and carried out in much detail by Colonel Reid. I have neither ability, nor at present space, to make more than a few brief remarks on this subject. Are not storms exceptions to the general winds, or, atmospheric cvirrents ; not the causes of them ? * Variable winds are almost con- tinual, except during short intervals of calm ; but hurricanes, or even ordinary storms, are rare. May not opposing or passing cur- rents cause eddies, or whirls, on an immense scale in the air, not only horizontal, but inclined to the horizon, or vertical ? In laying a ship to, during a storm, there are other points to con- sider besides the veering of the wind ; such as the direction of the sea, with or against a current, &c. I cannot agree with Colonel Reid, in his remarks (page 425) about the " problem to be solved," or in his " Rule for laying ships to in hurricanes." I never myself witnessed a storm that blew from more than fifteen points of the compass, either successively, or by sudden changes. In most, if not all of the stcJrms to which 1 can bear any testi- mony, currents of air arriving from diiFerent directions appeared to succeed each other, or combine together. One usually brought ' the dirt,' to use a sailor's phrase, and another cleared it away, after driving much of it back again, often Math redoubled fury. One of these currents was warm and moist — another cold and dry, compa- ratively speaking. While one lasted, the barometer feU, or was sta- tionary ; with another it rose. At all places I have ^•isited, or of which I have obtained notices on the subject, the barometer stands high with easterly, and comparatively low with westerly winds, on an average. Northerly winds in the northern hemisphere affect the barometer, like southerly winds in the southern hemisphere. No. 47. Tides. At the end of the year 1833, I received from Mr. Whewell a copy of a work for which seamen in general are deeply indebted to him. It * Reid's Law of Storms, p, 120, &c.