between 200 and 30° S. lat., and here the veering from S.E. by E. to N.E. might indicate the passage of the storm to the northward, but generally in higher latitudes than 23° S.; in these localities cyclones re-curve, moving to S. and S.E. A case, therefore, of veering from S.E. by E. to N.E. in latitudes higher than 23° S. would be regarded by the commander as very suspicious, and he would look out for his bad weather to the W. and S.W., rather than to the N. and N.E.

But what is a commander to do to avoid the fury of an atmospheric wave, should it become inconveniently strong? In the Journal compiled by Professor Meldrum, the strongest wind recorded in either section of the wave-i. e. N.E. or S.W.-is 9, or a close-reefed topsail gale, which is equal to a pressure of 23 lbs. on the square foot, as determined by Mr. Morton at the Cape of Good Hope; the mean strength of the N.E. being 5.2, or a moderate fresh breeze, with a pressure of 8 lbs., while that of the S.W. is 4.8, or very nearly the same. The commander has clearly not the chance of manoeuvring, as, in a revolving storm, the wind appears to be straight lined, and each section of considerable length. If his course be westward, he may be every moment approaching the trough, where the wind is strongest; how to avoid it does not clearly appear. With such winds his best course seems to be to make himself as snug as possible, to prepare for the strongest wind on record in these localities, and to keep a sharp look-out for the change. If a rotatory storm come rolling on between the N.E. and S.W. winds, so much the better, provided it does not exceed the strongest wind of the wave, especially if he be caught on the southern quadrant, for his ship will then be carried by the winds of the southern border into the S.W. stream; but if he be caught on the eastern quadrant, then he is soon headed off his course, and must round-to while the westerly winds pass over him; they will quickly be followed by the S. W. stream.

It would appear that when the Fanny Fisher' fell in with the gales above alluded to she was considerably to the eastward of the locality in which cyclones recurve, viz. a

space of 100 square, comprised between 20° to 30° S. lat., and 55° to 65° E. long. It is exceedingly unlikely that 15° east of this locality a cyclone should bear down upon a ship from N.E., or its centre pass a little to the northward of it.

Since the preceding paragraphs were written, the writer has most carefully examined Professor Meldrum's paper, and finds not only the general north-east and south-west winds, as laid down in the charts, accompanying it, but some remarkable curvilinear movements, as indicated in fig. 3, not noticed by the Professor. The space devoted

to this article precludes further remarks here, with the exception that, in the larger segment of the diagram, the wind is seen as blowing in a contrary direction to that indicated by the 'Law of Storms.' In fact it is, so Fig. 4.

Fig. 5.

Fig. 6.

far as the writer is aware, a new phenomenon, and will make the third kind of anemonal movement with which we are now acquainted: the atmospheric wave of Dove, illustrated in figs. 1 and 2; the rotatory storm of Redfield and Reid, illustrated in figs. 4 and 6; and the cyclonic converging segments as illustrated in figs. 3 and 5.

The Pacific Ocean.-Our knowledge of the meteorology of the Pacific is at present so small, especially when compared with that of the Atlantic and Indian Oceans, that we cannot do better than to request that all masters of vessels will co-operate, while sailing over any of its waters, in duly filling up the spaces in the weather-book.

In the previous sketch of the localities for the more important observations, it will be seen that within the tropics there are three which demand the greatest regard.

I. The Archipelago between the two Americas, more particularly comprised within the 40th and 120th meridians west longitude, and the equator and the 40th degree of north latitude. As a general principle, we should say that vessels within this area should observe the barometer at every hour appointed by the Board of Trade. Its eastern portion includes the lower branches of the storm paths, and on this account is peculiarly interesting, especially in a barometric point of view.

II. The Northern portion of the African Continent, including the Sahara or Great Desert.-This vast radiating surface must exert considerable influence on the waters on each side northern Africa. Vessels sailing within the area comprised between 40° west and 70° east and the equator and 40th parallel, should also make observations at the same hours.

III. The great Eastern Archipelago.-This presents a somewhat similar character to the western; like that, it is the region of terrific hurricanes, and it becomes a most interesting object to determine its barometric phenomena; the system of observation appointed by the Board of Trade may therefore be resorted to within an area comprised between the 70th and 140th meridians, and the equator and the 40th degree of north latitude.

The southern hemisphere also presents three important localities, the prolongations of the three tropical areas. It is unnecessary to enlarge upon these, as ample instructions have been already given. We may, however, remark,

with regard to Australia, that the observations above recommended should be made within the area comprised between the 100th and 190th meridians east, and the equator and the 50th parallel south, and hourly ones in the immediate neighbourhood of all its coasts.

EXTRA OBSERVATIONS.

In reference to certain desiderata that have presented themselves in the course of my researches on this subject (see Report of the British Association for the Advancement of Science, 1846, p. 163), the phases of the larger barometric undulations, and the types of the various seasons of the year, demand particular attention and call for extra observations at certain seasons: of these, three only have yet been ascertained-the type for the middle of November, the annual depression on or about the 28th of November, and the annual elevation on or about the 25th of December. The enunciation of the first, in reference to London and the south-east of England, is as under: "That during fourteen days in November, more or less equally disposed about the middle of the month, the oscillations of the barometer exhibit a remarkably symmetrical character, that is to say, the fall succeeding the transit of the maximum or the highest reading is to a great extent similar to the preceding rise. This rise and fall is not continuous or unbroken; in some cases it consists of five, in others of three, distinct elevations. The complete rise and fall has been termed the great symmetrical barometric wave of November. At its setting in, the barometer is generally low, sometimes below twenty-nine inches in the western part of Europe, especially in the neighbourhood of Ireland. This depression is generally succeeded by two well-marked undulations, varying from one to two days in duration. The central undulation, which also forms the apex of the great wave, is of larger extent, occupying from three to five days; when this has passed, two smaller undulations corresponding to those at the commencement of the wave

make their appearance, and at the close of the last the wave terminates." With very slight exceptions, the observations of several years have confirmed the general correctness of this type.

The symmetrical wave has been observed in Dublin; its progression has been ascertained in a south-easterly direction as far as Munich, and M. Lais has traced similar barometric movements in November, 1854, from the Bristol Channel to the Black Sea. In the autumn of 1856 it passed over Portugal, Spain, and the eastern portion of the Mediterranean, as appears from the log of Lord Gifford's yacht the Fair Rosamond.' The close or termination of the great November wave is mostly stormy. Mr. Milne alludes to the close of November as being generally a stormy period, and we find, from the 'Fair Rosamond's ' log, that similar weather occurred in the Mediterranean during the last week of the month in 1856. It would be well if logs in every respect similar to that kept by Lord Gifford were numerous. Masters of vessels sailing on the Atlantic between 30° and 60° N. latitude and the meridian of Greenwich and 40 W. longitude, would do well to keep such. We cannot speak too highly of the value of the one before us, and we hope that so good an example will be extensively followed, not only over the area above specified, but also in the North Sea; off the coasts of France, Spain, Portugal, and the northern parts of Africa; and in the Mediterranean.

It is highly probable that movements of a somewhat similar character exist in the southern hemisphere. The November wave is generally preceded by a high barometer and succeeded by a low one, and this low state of the barometer is always accompanied by stormy weather. We are therefore prepared to seek for similar phenomena in the southern hemisphere, in those localities which present similar states of weather, such as the Cape of Good Hope and Cape Horn, and at seasons when such weather predominates. At present we know but little of such barometric movements as are above specified in the southern