100 MONTHLY WEATHER.REVIEW. Fl53vARTr, 1988
Meteorological statione thus far have bean established at Baba, Barragmetal, Chobo, Rocafuerte, and Tonguel, to which 45 others are being selected.
ISVENUSCLOUDCOVERED?
Mr. Evershed has taken many photographs of the s ectrum of Venus in recent years for thep ose (inter &a) of endeavoring to detect the Eiastem.t and of testing his own hypothesis that the earth has an effect on the atmospheric circulation of the sun. In the course of this work he found, to his surprise, that a much longer exposure time was needed than was the case in photo- graphing the spectrum of a cumulus cloud OP whch the
sun was shining (Monthly Notices R. A. S., November). Mr. Evershed espected the time to be shorter, for the intensity of sunli ht on Veuus is 1.92 times as eat as on the earth. howing for the absorption of ?enus's atmosphere he concludes that if Venus were covered with clouds simdar to our cumulus clouds the exposed time would be less on the former than on the latter in the ratio of 1 to 1.3, whereas the contrary is the case. He concludes that the atmosphere of Venus is not cloud laden, but that its lower strata contain much dust in suspension, veiling the surface features. This conclusion is smilar to that reached by Prof. Lowell from his obser- vations at Flagstaff. Mr. Evershed thinks that the values of the color indices assigned by Prof. N. H. Russell to the sun and Venus (+0.79 m. and + 0.78 m.) are mutually inconsistent, since they imply that no selective absorption takes lace in
decided selective absorption in the violet, as compared with his cloud spectra.--Nui!we (London), Feb. 19, 1920, p. 675.
Venus's atmosphere. Mr. Evershed finds evi a ence of
ROUND THE WORLD ON A VOYAQE OF 1,OOO MILES.
After a voyage of 76 days from Melbourne, the barque InvmeiU arrived at Bunbury, western Australia, on July 6 for Bunbury to load 'arrah for South Africa, and soon after clearing Port Philh Heads she struck a strong westerly gale, whch continue : for days. The vessel was driven out of her course, and through the straits. When on the other side of Wilsom Promontory the wind veered west, and the vessel was driven up the New South Wales coast. When the Invemeill was to the south of Sydney Heads the weather moderated, and so the captain decided to o on to Sydney. After a f o r t stay m Sydney he left a a h , and found the westerly winds still a t their hei ht. b e then decided that instead of crossin the Bight EB e would go with the westerly wind around e world. Five da after sett' sail he found himself at the north end New Zealan having one a distance of approximatel 1,200 nauticd nliles. h s he considered a remarkaby s good record. As an average the barque traveled 240 miles a day. In
28 more days he was roun the Horn with the wind
still in a helpful direction % trip continued for a further 33 days, when he found hmself a t St. Paul Island in the mid-Indian Ocean. Frqm thence on to Bunbury the trip took 16 days. The trip was a fast one, owing to the steady westerly winds. Capt. Shippen him- self estimated that the voyage would take approximately
09" Y &
from S dney to Bunbuq occu-
his endeavor to go from F apt. Shippen estimates
Melbourne to Bunbury, and his average sailing tame was 292 miles a day. He considers that such a passage has never been made before by a mariner, and expresses the
o inion that he is doubtful if it will ever be repeated.- 2verpool ~mmta~ ~f cmwce.
REFERENCES TO LITERATURE ON ICE CAVES.
The ex lanation of the phenomena 'observed' in the ico
1919, pp. 470 ans495, reprinted in MONTHLY WEATHER REVIEW, Nov., 1919, p . S03-804), is looked upon with
in many such caves in various parts of the world. There is one proposition that indicates possible formation of ice in the summer time, namel when air is so dry
however, is u&kely. In most cases heavy ice is formed late in minter and does not melt until far into the summer time. The following references supply much information on this subject:
Qlaciereg, or freezing caverns. E. 8. Balch, Philadelphia, 1900. 326 p. Includea bibliography. The Swexfem- ice mine and its explanation. M. 0. An- drewa. P a p @ S&nq arOnUly vol. 82,1013, pp. 28&288. Ice caves. A. M. Mdler. Scwnec, N. 8.37, 1913, . 980481. Iowa Qeolagical Survey, Annual Report, vol. &, 1905, pp. 142- 146. Includes referencee. Ice caves aad froaen web as metcorological phenomena. H. H. I3imW. MONTHLY WEATEEB REVIEW, vol. XXIX, 1901, pp. 366-371. Gives references. Ice caves and freezing wells. MONTHLY WEATEEB REVIEW, vol.
The Dearah ice cave and its explanation. A. F. Komrik. Beinr- ti& Amaimn S u p p h m t , vol. 46, 1898, p. 19W19l&Q. Ice caves of France and Switzerland. Rev. 8. F. Bmwne, Inndon, 1865. 315 pp. '
Qeology and mineral deposits of the Colvilb Indiaq Reserva- tion, Washington. J. T. Pardee. 0. 8. asObgical &rrcMy
Bulktin 677, 1918. pp. 170-171.
cave a.t 8 ouders ort, Pa. (Sden.tiJic American, May 6,
some doubt, in view o a the well-understood conditions
that the dew oint is below the P reezing point. This,
XXIX, 1901, pp. 809-510.
- W. J . Humphreys.
THE WAVERAISINQ POWER OF NORTHWEST AND SOUTH WINDS COMPARED.
Mr. C. Kennedy, meteorological observer for the Weather Bureau on the British S. S. Indian, Capt. I. Chadwick, in a recent communication, aaks the following interesting question:
Why it is, that when we experience a wind from a northerly direction, eepeually northweaterl , the sea rises very quickly? On the contrwy, if we experience a sout&rl wind, and if of a strong force, there is very little sea. This ie in nortiern latitudea.
The followin explanation of the point raised b Mr.
and Dr. C. F. Brooks of the deather Bureau:
(1) Northweat winds d y are stron er than southerly winds over the America-tc+En land trade routes of t!e Atlantic and for thie m n alone should 've f q e r waves, since the wave effect i n m - much faster t , the strength of the wind. (2) Over much of this route the winds of winter (eeason of rough water) are prevailingly northwest. Hence, there usually are Borne waves of the northweat-wind type, due either to actual winds at the time and place, or to persistence of wavea from more or leee pmious and distant storma. Any. freshening of the northwmt wind would then only increase the exlsting wave system. The creets of the existing
waves would lie at right angles, roughly, to the new wind, and thew
mdes would be expoaed to its maximum premure. On the other hand a wind from the south would, at &t, meet with less surface obstruction (because blowing rather along the waves than againnt their aides) and thus be leas efficient in raising a sea.
(3 A given wind haa a greater waveproducin effect on an already
rougher in winter than in summer, owing largely to the greater fre- quency and severity of s w d- the cold BBBBon than during $e warm one, it follows that a gnren wmter wmd (usually northweat) III
likely to produce a higher eea than ie an equal summer wind (umdly
Kennedy haa % een offered b Prof. W. J. Hump L e y~
roug h sea than on a imooth one. Hence, an &e ocean p d l y m