322 



NATURE 



iFeb. 



The variable star of Ceraski, the true period of w hich was 

 determined at Harvard College, is referred to ; systematic obser- 

 vations have been made upon it. The Report describes the 

 progress made in observations with the "meridian photometer," 

 whereby it is intended to determine the light of all stars visible 

 to the naked eye between the North Pole and N.P.D. 120°. The 

 principal want of the Obser\atory at the present time is stated 

 to be the means of publication of these and other clashes of 

 observations, the large number of volumes issued during the last 

 five years having exhausted the funds specially appropriated for 

 defraying expenses of publication. 



Ceraski's Variable Star T Cephei. — Prof. Julius 

 Schmidt, from his own observations of minima of this variable 

 in the last five months of the past year, finds reason to conclude 

 that in that interval each succe-sive period was longer by 

 0'oS753m. or 5'25s. than the preceding one, and has calculated 

 the times of minima upon this assumption between lune II, 

 iSSo, and February 15, 1881. For elements with this correc- 

 tion to the period to be applied, he adopts for his starting- 

 point — 



Minimum ... 1880, December 7, loh. 67m. 

 Athens M.T. + 2d. Ilh. SO-8i2m. E. 

 E being the number of periods from December 7. Thus the 

 next minimum is found to occur on February 5, at 6h. S0"3m. 

 Athens time, or at 5h. 15 ■4m. M.T. at Greenwich. Prof. 

 Schmidt has remarked what we believe was soon detected by 

 Mr. Knott from his observations in October last, that for more 

 than two hoars about the minimum there is no perceptible vari- 

 ation of brightness ; decrease and increase are very rapid, 

 particularly the latter. 



Swift's Comet, 1880 <•. — The Superintendent of the Obser" 

 vatory at Washington, Admiral Kodgers, communicates to 

 Scifitcc of Januiry 10, an orbit of this comet which has been 

 calculated by Prof. Frisby from three meridian observations 

 made there on October 25 and November 7 and 25, and without 

 any assumption as to the periodic time. The revolution resulting 

 from this application of the general method is about 2178 days, 

 or a little less than six years, and thus the conclusim arrived 

 at by MM. Schulhof and Bossert of Paris, and Mr. S. C. 

 Chandler of Boston, U.S., receives confirmation. From the 

 position of the orbit it happens at present that only every second 

 return to perihelion can be made available for observations. 



Baron Dembowski. — Practical astronomy has sustained a 

 severe loss in the death of Baron Ercole Dembowski, which 

 took place on the evening of the 19th ult. at Monte, Frazione di 

 Solbiate, Arno. Few have attained as great skill or exhibited 

 greater industry and patience in that somewhat difficult and 

 tedious branch, the measurement of the double stars, to which 

 the Baron specially devoted himself, and we hope some means 

 may be found of publishing in a collective form the results of 

 his long-continued labours in this direction. 



METEOROLOGICAL NOTES 



Our readers will learn with much satisfaction that Sweden 

 has resolved to take part in the international meteorological 

 and magnetical observations in the Polar regions, and arrange- 

 ments have been made for carrying on the observations from 

 June I, 18S2, till June i, 1883. The house erected at Masselbay 

 in Spitzbergen by Nordenskjold's expedition, is still in good 

 condition, and will be fitted up for the observatory. In connec- 

 tion with the Spitzbergen Observatory, Haparanda, at the head 

 of the Gulf of Boothnii, is to be created into a first-class obser- 

 vatory, and furnished with Theorell's self-registering and print- 

 ing meteorological apparatus ; and all other observations will 

 be made which are expected of a first-class observatory. M. 

 Hjeltstrom is appointed director of the Haparanda Observatory. 

 The funds to meet the expenses of the expedition and the two 

 observatories have been most generously supplied by M. L. O. 

 Smith, Stockholm. Prof. Hildebrandsson, the eminent Swedish 

 meteorologist, has been entrusted with the discussion of the 

 observations made by Prof. Nordenskjold on the celebrated Ve^a 

 Expedition, to the publication of which meteorol agists will look 

 forward with the liveliest interest. 



In his fourteenth contribution to meteorology Prof. Loomis 

 returns to the discussion of the intere-ting question of the course 

 and velocity of storm centres in tropical regions. In a previous 

 communication he had shown that in middle latitudes the average 



progress of storm centres corresponds pretty closely with the 

 average direction of the prevailing wind of these latitudes. In 

 marked contradistinction to this result is that now obtained 

 regarding the course of the intertropical cvclones which occur 

 within the region of the North-east Trade Winds. These 

 cyclones, instead of following the ordinary course of the Trades 

 towards the south-west, advance westward, but in a direction 

 somewhat north of west. 



During the winter months, storms while crossing the United 

 States frequently advance during a part of their course from 

 north-west to south-east. This course is followed most fre- 

 quently in the region between the Rocky Mountains and the 

 Mississippi, is seldom continued as far south as lat. 30°, and the 

 storm centre, after reaching its most southerly point, often 

 changes its course towards the north-east. Storms which cross 

 the United States north of lat. 38° generally pursue a course a 

 little to the north of east ; while those which come from south 

 of that latitude pursue a course nearly n^rth-east. During the 

 summer months however few storms travel south of lat. 38', and 

 during this part of the year the average course of storms is 

 almost exactly towards the east. 



Prof. Loomis next institutes a comparison between the West 

 India hurricanes and those of the Bay of Bengal, China Sea, &c. 

 The average course of the latter is towards the west, ranging from 

 1 3° south of west to 86° north of west, which agrees clo ely in this 

 respect with tl>e general course pursued by West India hurricanes. 

 The velocity of their onward ciurseis however markedly different, 

 being only about eight miles per hour, which is less than half 

 the average velocity of the West India cyclones. The average 

 latitude when the course becomes north is nearly lat. 20°, being 10" 

 more to southward than in the West Indies, and the velocity 

 during this part of the course is only about nine miles an hour. 

 Ultimately the cyclones cun-e round and pursue a course nearly 

 east-north-east, with a velocity of onward movement scarcely 

 reiching ten miles an hour, or le s than half of the velocity found 

 f jr West India hurricanes. Lastly, while in the West Indies 

 cyclones or hurricanes have been found no farther south than 

 lat. 10° N., in Southern Asia they have occurred as far south 

 as lat. 6° N. 



The concluding part of the Contribution is taken up with an 

 examination of those storms of middle latitudes which advance 

 in a westerly direction. In these cases, which may be regarded 

 as abnormal directions, it is found that the wind is generally 

 greatest on the east side of the low centre of the storm. While 

 there are thus on the east side of the low"pressare areas, causes 

 tending to increase pressure on that side, there are different con- 

 ditions on the west side tending to divert the winds westward, 

 and this, Prjf. Losmis thinks, is the most important reason why 

 in such cases the storm centres advance to westward. In the 

 United States, over the Atlantic, and in Europe, the influence of 

 one area of low pressure upon another is a very common cause 

 of abnormal movements of storm centres — such, for instance, as 

 the coalescence of two low areas into one, resulting occasionally 

 in an apparent westerly movement of the centre of lowest 

 pressure. 



The " Results of Meteorological Observations made at 

 Mauritius during 1S77 " fully sustains the high reputation of Dr. 

 Jleldrum's previous reports for fulness of detail, accuracy, and 

 special observations not usually given in meteorological reports. 

 Tbe hourly monthly values have been calculated from the 

 readings of the barograph for the year, and a valuable table is 

 appended tj this part of the report (p 5), showing the mean 

 monthly diurnal variation of atmospheric pressure for the three 

 years 1875-77. The value of these results will be greatly 

 enhanced when the thermograph which has been received has 

 been got into working order. A comparison, a very satisfactory 

 one, is made of the barograph reidings with those of the 

 standard barometer. As in 1876 the wind during 1877 attained 

 its annual maximum velocity in the colder months from June to 

 August, and its minimum in the warmer months, from November 

 to March; and its diurnal maximum velocity from 11 a.m to 

 2 p.m., and its minimum from about 2 to 5 a.m. The de- 

 partures, however, from these times are such as to point to a 

 considerable number of years' observations as required before 

 the true average can be ascertained. Thirty-one stations for 

 recording the rainfall are now in working order, and in each 

 case the annual amounts available from 1862 are printed, and 

 the averages of the years given for each station. Mean tempe- 

 ratures for seven stations appear in the reno t, the three highest 



