March 13, 1890] 



NA TURE 



44: 



it is carried out will do much for biological research, viz. 

 that steps be taken to establish and endow a central 

 biological station at Port Jackson. Among the other 

 reports may be mentioned one on the Polynesian races 

 and Polynesian bibliography. 



At the final meeting of the General Committee of the 

 Association new special Committees were appointed to 

 investigate and report on the following subjects : wheat 

 rust, the manner of laying out towns, the preparation of 

 geological maps, the arrangement of museums, the 

 fertilization of the fig, Australian tides, and the present 

 state of knowledge with regard to Australasian palaeonto- 

 logy. A Committee was also appointed to formulate a 

 scheme for obtaining practical assistance from the various 

 Colonial Governments in the collection of material for 

 research — chemical, geological, or biological. Other 

 special Committees were appointed for the publication 

 of the Transactions and for the revision of the -laws of the 

 Association. 



The next meeting is to be held in Christchurch, New 

 Zealand, probably in January 1891 ; and Sir James Hector 

 has been elected President, and Prof. Hutton, Secretary. 

 It has also been decided to hold the fourth meeting in 

 Hobart, Tasmania, so that the Association will not again 

 meet on the mainland for three years. To adventure so 

 far as Christchurch is somewhat bold in so young an 

 Association ; but the success of the Melbourne meeting 

 has demonstrated its usefulness and popularity, and war- 

 rants the belief that many will cross the water next year. 

 There is even a strong hope felt by some that the occa- 

 sion and the place may tempt a few of the members of 

 the parent British Association to make the longer voyage 

 from home, and see for themselves what is being done 

 and what waits to be done for science at the antipodes. 



Orme Masson. 



METEOROLOGICAL REPORT OF THE 

 " CHALLENGER " EXPEDITION} 



"PREVIOUS to 1872, discussions of the fundamental 

 -*■ problems of meteorology relating to diurnal changes 

 in atmospheric pressure, temperature, humidity, wind, 

 and other phenomena, may be regarded as restricted to 

 observations made on land. It had then, however, be- 

 come evident that data from observations made on land 

 only, which occupies about a fourth part of the earth's 

 surface, were quite inadequate to a right conception and 

 explanation of meteorological phenomena ; and hence, 

 when the Challenger Expedition was fitted out, arrange- 

 ments were made for taking, during the cruise, hourly or 

 two-hourly observations. These observations were pub- 

 lished in detail in the " Narrative of the Cruise," Vol. II. 

 PP- 305-74) and are still by far the most complete yet 

 made on the meteorology of the ocean. 



Elaborate observations were likewise made on deep- 

 sea temperatures, which were at once recognized as 

 leading to results of the first importance in terrestrial 

 physics, and opening for discussion the broad question of 

 oceanic circulation, on a sound basis of authentic facts. 

 Preliminary, however, to any such inquiry, a full discus- 

 sion of atmospheric phenomena was essential, requiring 

 for its proper handling maps showing the mean tem- 

 perature, mean pressure, and prevailing winds of the 

 globe for each month of the year, with tables giving the 

 data from which the maps are constructed. In other 

 words, what was required was an exhaustive revision and 

 ratification of Dove's isothermals, 1852 ; Buchan's iso- 

 bars and prevailing winds, 1869 ; and Coffin's winds of 

 the globe, 1875. 



' " Report of the Scientific Results of the Voyage of H.M.S. Challenger 

 during the Years 1873-76.-' Prepared under the superintendence of John 

 Murray. LL.D. " Physics and Chemistry," Vol. II., Part V. "Report on 

 Atmospheric CircuLition. " By Alexander Kuchan, M.A., LL.D. 



The work was entrusted to Mr. Buchan, of the Scottish 

 Meteorological Society, in 1883, and was published in the 

 beginning of this year. In addition to the tables of the 

 appendices, giving the results of the Challenger observa- 

 tions, the more important are those giving the mean 

 diurnal variation of atmospheric pressure at 147 stations 

 in all parts of the world ; the mean monthly and annual 

 pressure at 1366 stations ; a similar table of temperatures 

 at 1620 stations ; and tJie mean monthly and annual 

 direction of the wind at 746 stations. It is believed 

 that these tables include all the information at present 

 existing that is required in the discussion of the broad 

 questions raised in the Report, which includes, with the 

 exception of the rainfall, all the important elements of 

 the climates of the globe. 



The Report itself is divided into two parts, the first 

 dealing with diurnal, and the second with monthly, 

 annual, and recurring phenomena. This is the first 

 attempt yet made to deal with the diurnal phenomena of 

 meteorology over the ocean — the temperature, pressure, 

 and movements of the atmosphere, together with such 

 phenomena as squalls, precipitation, lightning, and 

 thunderstorms. 



In equatorial and subtropical regions, the mean tem- 

 perature of the surface of the sea falls to the daily 

 minimum from 4 to 6 a.m., and rises to the maximum 

 from 2 to 4 p.m., the amount of the diurnal variation 

 being only o''9 F. In the higher latitudes of the 

 Antarctic Ocean, the diurnal variation was only o°"2. Of 

 the four great oceans, the greatest variation was i°'o in 

 the North Pacific, and the least o°'8 in the Atlantic. This 

 small daily variation of the temperature of the surface of 

 the sea, shown by the Challenger observations, is an 

 important contribution to physical science, being in fact 

 one of the prime factors in meteorology, particularly in 

 its bearings on the daily variations of atmospheric 

 pressure and winds. The diurnal phases of the tem- 

 perature of the air over the open sea occur at the same 

 times as those of the temperature of the surface, but the 

 amount of the variation is about 3°'o, and when near land 

 the amount rises to 4°'4. The greater variation of the 

 temperature of the air, as compared with that of the 

 surface of the sea on which it rests, is a point of much 

 interest from the important bearings of the subject on 

 the relations of the air, and its aqueous vapour in its 

 gaseous, liquid, and solid states, and the particles of 

 dust everywhere present, to solar and terrestrial radia- 

 tion. Thus the air rises daily to a higher and falls to a 

 lower temperature than does the surface of the sea on 

 which it rests. 



The diurnal variation in the elastic force of vapour in 

 the air is seen in its amplest form over the open sea, the 

 results giving a curve closely coincident with the diurnal 

 curve of temperature. But near land, the elastic force 

 instead of rising towards, and to, the daily maximum at 

 noon and 2 p.m., shows a well-marked depression at 

 these hours, and indicates no longer merely a single, but 

 a double maxima and minima. In other words, the curve 

 now assumes the characteristics of this vapour curve as 

 observed at all land stations, or where during the warmest 

 hours of the day ascending currents rise from the earth's 

 surface, and down-currents of drier air take their place. 

 An important point specially to be noted here is that over 

 the open sea, hygrometric observations disprove the 

 existence of any ascending current from the surface of 

 the sea during the hours when temperature is highest. 

 On the other hand, the curve of relative humidity is 

 simply inverse to that of the temperature, falling to the 

 minimum at 2 p.m. and rising to the maximum early in 

 the morning. 



As regards the diurnal variation of the barometer, it is 

 shown that the special forms of the monthly curves are, 

 in their relations to the sun, direct and not cumulative 

 as is the case with most of the monthly mean results of 



