followed by the N. W. wind in spring and autumn. This class of storms pass off toward, and doubtless over the track, of our European steamers and packets. I know this, for I witness it nearly every month in the year. It is not a matter of speculation, but of actual, long-continued observation. Probably, as one approaches the Gulf Stream, and when over it, its induced winds may be more violent. It is time our navigators understood this; and that all the gales of the North Atlantic, certainly, are not rotary; and do not approach from the S. W. in the same manner as the class investigated by Mr. Redfield do. Where a fresh southerly or south-westerly wind is followed by any considerable cirro-stratus or stratus-condensation, it is usually of this character. The following diagram exhibits the peculiarities of this class of storms. It is intended to represent the same storm or belt of showers, on _two successive_ days, and, of course, its usual rate of southerly extension: [Illustration: Fig. 21.] This class of storms, or belts of showers, present the following succession of phenomena in summer: 1. Still warm weather, one or more days. 2. Fresh southerly wind, one or more days; if more than one, dying away at the S. W., at night-fall, but continuing into the evening of the day before the belt of condensation arrives. 3. Belt of condensation, with or without rain or showers, with the easterly wind blowing axially, if the condensation is heavy and the belt wide; westerly if the condensation is feeble or the belt narrow--the clouds moving about E. N. E. 4. Cooler air, light N. W. in summer, heavy N. W. in autumn, winter, and spring. And, the next period-- 5. Still warm weather or light airs. 6. Southerly wind, fresh. 7. Belt of condensation. 8. Cool northerly wind. And so on, successively, unless broken in upon by some other class. Sometimes these periods are exceedingly regular, at other times the other classes prevail. I have much reason to believe that this is the _normal, periodic_ provision for condensation of our portion of the northern hemisphere, and probably of every other where rain falls regularly in the summer season, and that the other classes are exceptions, as the hurricanes are exceptions to the normal condition of the weather every where. Perhaps in some seasons, during the northern transit, the exceptions may equal the rule, but I do not now remember such a season. In other years nearly all the storms are of this character. Thus, Dr. Hildreth (in Silliman's Journal for 1827), speaking of the year 1826, in a note to his register of that year, says: "There have been, this year, an unusual number of winds from N. or N. W. Nearly every rain the past summer has been followed with winds from the northward, when, in many previous summers, the wind continued to the southward after rain." The immediate occurrence of northerly wind after the passage of the belt of condensation, is a peculiar feature of this class of storms.