Jan. 15, 1880] 



NATURE 



265 



In iSjj Clausen made what appears a more likely suggestion, 

 that the comet of July, 1819, was identical with the second 

 comet of 1 766, which was observed for a short time only by 

 Messier at Paris, before perihelion passage, and after perihe- 

 lion by La Nnx in the Isle of Bourbon, though but roughly. 

 Eurckhardt found, in 1S17, that the whole of the observations 

 could be represented within their probable limits of error by an 

 ellipse with a peril d of revolution little over five years. The 

 planet Jupiter must have acted powerfully upon Winneekes 

 comet towards the end of the last century, and, so far as we can 

 see, it appears possible that the perturbations occasioned at that 

 time may account for the differences in the orbits of 1766 and 

 1819. If Burckhardt's elements for the comet of 1766 are 

 approximately correct, as seems probable, it may have been 

 detected at its first visit to peiihelion in the actual form of orbit, 

 perhaps at its first visit after being fixed in the system through 

 the agency of Jupiter. We know that Brorsen's comet of short 

 period was discovered under similar conditions. 



METEOROLOGICAL NOTES 

 Six years ago wc remarked (Nature, vol. ix. p. 164) that 

 what was required in order to describe and classify many forms 

 of clouds, were accurate delineations of these forms in their 

 different aspects, and systematic inquiries as to the relations of 

 clouds to the mode of their formation, to the states of the 

 aqueous vapour composing them, and to the varying elasticity, 

 temperature, and electricity of the atmosphere. Since then but 

 slow progress has been made, the great desideratum being the 

 contribution of data in a form on which science can lay its 

 hands. A contribution of data of this sort has just been made 

 by Dr. Hildebrandsson, the director of the meteorological ob- 

 servatory of U psala, in a memoir on the " Classification of Clouds 

 employed at theObservatory,"illustrated with sixteen photographs 

 of clouds. The photographs, which are about nine by seven 

 inches are very fine ones, and well chosen out of a large num- 

 ber taken under the direction of Dr. Hildebrandsson, to illus- 

 trate the different forms of cloud and their more important 

 modifications and transitional states. The series repiesenting 

 the more marked changes from the delicately-pencilled cirri of 

 the flimsiest texture to the nimbus of a rain-cloud is a most 

 instructive one ; as is also the series showing the strato-cumulus 

 as commonly observed during the winter season in Scandinavia. 

 The relations of the varying forms of clouds to cyclones and 

 anticyclones which pass over Sweden is just touched on, but this 

 important phase of the inquiry we hope Dr. Hildebrandsson will 

 again return to, seeing he can so readily refer to the observa- 

 tions of his observatory, which give so complete and satisfactory 

 a record of the various fugitive phenomena of the weather 

 changes of that part of Sweden. Dr. Hildebrandsson's photo- 

 graphs of clouds may be studied with equal interest and pro- 

 fessional advantage by artists as well as by meteorologists, it 

 being scarcely possible to point to any department of art standing 

 more in need of a thorough reformation than the cloudscapes of 

 our landscape painters. 



The Hydrographic Committee of the French Marine has at a 

 recent sitting sanctioned the publication of the last four of the 

 series of sixteen wind-charts prepared by M. L. Brault. In 

 these four charts the winds of the Pacific are dealt with, the 

 winds of the North Atlantic, the South Atlantic, and the Indian 

 Ocean being discussed in the twelve charts previously prepared. 

 In preparing these sixteen charts M. Brault has made use of 

 upwards of 3,000,000 observations made over the oceans and 

 continents of the globe. The chief results referring to the 

 circulation of the atmosphere show as regards the South Pacific, 

 which presents the largest expanse of ocean least influenced by 

 land, a belt of calm or light winds near the equator ; then the 

 well-known south trades ; to these succeeds a belt of winds 

 variable as regards direction, but blowing with a force at least as 

 great as the trades ; and lastly, westerly winds, varying little, 

 though more than the trades, in direction, and incurving upon 

 the South Pole the nearer they approach it, and blowing 

 much stronger than the trades and variables. As regards the 

 other oceans, the disturbing influence of the land is felt in pro- 

 portion to the extent of the continents which surround them, the 

 disturbing influence reaching its maximum in August and 

 January, in other words in those months when atmospheric 

 pressure of the continents is in greatest excess or defect compaied 

 with that of the ocean as shown by the isobaric chnrts of the 

 globe. 



M. L. TEISSERENC he BoRT has prepared isrbnormal 

 charts of the temperature and pressure of the atmosphere, with 

 the view of comparing, with some exactness, these two all- 

 important factors of atmospheric circulation. He finds that 

 when any region presents an excess of temperature, either abso- 

 lute or relative to that of places in the same latitudes, a baro- 

 metric minimum tends to be formed, and that the coincidence 

 between the minimum of pressure and the maximum of tempera- 

 ture is almost complete. The tendency results in either a well- 

 defined area of low pressure, or in the less pronounced form of a 

 simple distortion of the isobaric lines as they cross the region of 

 relatively high temperature. On the other hand, barometric 

 maxima tend to establish themselves over regions whose tempera- 

 ture is either absolutely high or relatively so to the latitude, and 

 the tendency to an increased pressure is the more decided when 

 the region in question is surrounded by regions of low pressure. 

 At a meeting of the Botanical Society of Edinburgh, held on 

 Thursday, the Sth inst., Sir Robert Christison read a paper of 

 very considerable importance on the relative growth of the 

 trunks of trees during 1879 as compared with lb7S. Upwards 

 of two years ago Sir Robert set 011 foot a system of measure- 

 ment of the girths of a large number of well-grown trees in 

 Edinburgh and neighbourhood, the measurements being made 

 by himself with the same measuring-line, and the same circum- 

 ference to be measured secured by marking it at the time of the 

 first measurement with paint. The inclement character of the 

 summer months of 1879 as compared with 1S78 was described 

 by a reference to the daily maximum temperatures noted at the 

 Edinburgh station of the Scottish Meteorological Society, from 

 which it appeared that for the six months ending with Sep- 

 tember the mean for 1879 was fully 5° - o less than tor 1878, and 

 the deficiency of day temperature amounting to nearly io°o Of 

 II deciduous trees, exclusive of oaks, the deficiency of growth 

 during 1S79 as compared with 187S was 41 per cent. ; of 17 

 evergreens of the pine tribe, the deficiency was 20 per cent. ; 

 and of 7 oaks the deficiency was 10 per cent. The 7 oaks were 

 of different species, but they all gave results closely agreeing 

 with each other. We shall look forward with the greatest 

 interest to the annual reports of this investigation, which may 

 be expected to reveal novel and valuable results illustrative of 

 the bearings of meteorology on the growth of our forest trees. 



An interesting account of waterspouts observed on November 

 10, 1879, off Cape Spada, west of Canea, by Herr Miksche, has 

 been communicated by him to the Vienna Academy. About 

 9 A.M. some heavy thunder- clouds rose in the west in a clear sky, 

 reaching the zenith only after noon. One in advance, very 

 black, and low-hanging, gave, about ten minutes to one o'clock, 

 the phenomenon of the waterspout, a thick descending column, 

 of milk-white appearance, being formed from it. The amount 

 of downward gyrating force may be approximately estimated 

 from the fact that at the distance of some eighteen miles one 

 could distinctly see with the naked eye, a high round pedestal, 

 formed by the foaming sea-water, like the socle of a monu- 

 ment. After ten minutes' duration, the column lost its conical 

 form and began to assume a rectangular one ; w hile, at the 

 extreme eastern point of the cloud, a second waterspout was 

 formed, conical in shape and of the same hue and intensity as 

 the first. To this column also the sea presented a pedestal 

 visible to the eye. For fully five minutes the water discharge 

 continued with like intensity in both trombes. Precisely at live 

 minutes after 1 r.M., i.e., about a quarter of an hour after 

 formation of the firs trombe, an angular discharge of lightning 

 (without audible thunder) took place from the clouds at that part 

 into the sea ; then the trombe suddenly ceased, only the pedestal 

 continuing some time to show where it had been. The second 

 trombe remained unaffected five minutes longer, then was ex- 

 tinguished without lightning discharge, and without reverting to 

 the original conical form (as the first did). This fine display of 

 natural forces was quite finished at 1. 16 P.M., the clauds then 

 unitin" and pursuing their course eastwards. 



GEOGRAPHICAL NOTES 

 At the meeting of the Geographical Society on Monday last, 

 a letter was read from Mr. Thomson which had that day been 

 received via Mozambique, announcing the arrival of the East 

 African expedition at Mbungo, at the north end of Lake Nyassa, 

 on September 22. Mr. Thomson was u.iable to discover the 

 Uranga country and river, described by the late Capt. Elt >n as 

 lying near Merere's town, but he believes the river to be the 



