470 



NA TURE 



[March 15, 1888 



Line, still we are constrained to think that the south- 

 west monsoon is still part of the same system. If the 

 monsoon was independent of the trade, there must be a 

 belt of high pressure between the two ; and of this there 

 is absolutely no trace. 



We must therefore look to some explanation other 

 than the conception of an independent circulatory system 

 over the Bay of Bengal ; but materials are at present 

 •wanting to form a definite conclusion on the point at 

 issue. There are two ways by which the question could 

 be settled, 



A few sets of observations of cloud-motion on ships 

 coming up the Bay from southward, would almost in- 

 fallibly give decisive results. If the upper clouds over 

 the west winds, just north of the Line, come from the south 

 or south-east, the surface wind has been drawn across the 

 equator ; but if, on the contrary, the clouds drive more 

 and more from the north of west the higher they are, 

 then the circulation over the Bay of Bengal is not fed 

 directly by currents which have crossed the line. 



A set of daily weather charts for the whole Indian 

 Ocean would also clear away many doubts, When 

 differences of pressure are small, and winds are variable, 

 charts of mean monthly isobars, and of resultant winds, 

 are very delusive ; for the average relation of pressure, 

 wind, and weather, may be quite different from that on 

 any actual day. 



The materials at present available point unmistakably 

 to some connection between the anomalous wind and 

 weather in the southern portion of the Bay, and the local 

 ai'ea of low pressure over Southern India. It is very 

 conceivable that the whole width of the south-east trade 

 does not cross the equator with an unbroken front ; but 

 that for some reason or other a great local eddy may be 

 developed in the Bay of Bengal. No river ever flows 

 regularly, but is broken up into ripples and backwaters ; 

 and though there are many differences between the flow 

 of water and of air, still there are certain properties 

 common to the motion of every fluid. 



Very itw English meteorologists care much for 

 theoretical discussions of air motion ; but the Indian 

 workers use mathematics freely in their investigations. 

 Mr. Dallas calculates the flow of a current of air from 

 10° S. latitude to io° N., according to the formula given 

 by Mohn and Gulberg. He takes a gradient directed 

 N. 30° E., across the Arabian Sea, and notes the differ- 

 ence both of force and direction between the observed 

 and calculated winds. No doubt there is a certain 

 accordance between the results so obtained ; but still 

 there are errors, which, taken with other things, suggest 

 that the theory is still imperfect. 



According to the formula — a modification of Ferrel's 

 theory— when air flows northwards down a gradient, the 

 angle between the wind and the gradient should decrease 

 as we approach the equator, disappear altogether on the 

 line, and then gradually increase as we proceed further 

 north. But in practice the trade keeps steadily in the 

 south-east from about 20° S. almost to the equator, then 

 turns rather suddenly to south-west, and the monsoon 

 advances steadily in that direction from about 5° to 20'^ 

 N. In the opposite monsoon, the north-east winds run 

 steadily from about 20° N. down to the line, and then 

 turn rapidly to north-west. 



It is well known in our own latitudes that, though the 

 wind rotates in contrary directions round cyclones and 

 anticyclones, the sweep of the wind is usually less than 

 the curvature of the isobars would suggest. For instance, 

 if an anticyclone lies to the north of Great Britain, all the 

 winds will often be from about north-east instead of 

 sweeping gradually from north-east through east to south- 

 east. This and many other similar observations point 

 to a north-east and south-west set of the winds all over 

 the northern hemisphere, which has not yet been accounted 

 for by any theory. 



In conclusion, we may remark how thoroughly the 

 author has discussed the subjects of his memoirs ; though 

 some will doubtless differ considerably from him in the 

 theoretical portion of his work. India presents a field 

 foi research unique from that in any other part of the 

 world ; and those who are acquainted with the magnifi- 

 cent equipment, order, routine, and system of inspection 

 inaugurated by Mr. Blanford, will feel confident that 

 every year will add to our knowledge of a region that 

 presents the most fascinating problems to the student of 

 atmospheric dynamics. Ralph Abercromby. 



NO. 2 MUSEUM, KEW. 



THE Museum of Monocotyledonous Products in the 

 Royal Gardens, Kew, better known, perhaps, as 

 No. 2 Museum, which was recently closed for rearrange- 

 ment, has been again opened to the public. The entire 

 collection has been classified according to the plan of the 

 " Genera Plantarum," so that the whole of the collections 

 contained in Museums Nos. i and 2 are now arranged 

 according to the system adopted by Bentham and Hooker. 

 A new room which was added to the Museum a few 

 years since has now been utilized ; this has given space 

 that was much needed for the proper display of the 

 products of such important natural orders as Scitamine(s, 

 Bronieliacece, AuiaryllidecE, Liliaceo', Palinece, A rot dee, 

 Cyperacece, and Gramiiiacea. In the first named order, 

 a large number of valuable economic plants are included, 

 such as ginger, turmeric, cardamoms, arrowroot, bananas, 

 and others ; while m Li/iacecs we find sarsaparilla, aspara- 

 gus, onions, squills, medicinal aloes, and New Zealand 

 hemp. All these have had much more space given to them 

 than hitherto, and the fine collection of native New Zealand 

 garments made of the indigenous hemp {Phormium tenax), 

 which are rapidly becoming scarce, are now opened out 

 and fully shown. A very large increase of space has been 

 given to the PalmecB, and as it is one of the most im- 

 portant orders to mankind generally, especially in 

 tropical countries, it was but fitting that this unique 

 collection of palm products should be fully displayed. 

 In such a series as that at Kew it is difficult to particu- 

 larize any one e.xhibit as more important than another, 

 but we may draw attention to the fine set of specimens 

 illustrating the coco de mer, or double cocoa-nut of the 

 Seychelles {Lodoicea sechellarum). This comprises a 

 fine series of fruits, including a model of the fruit in which 

 the nut is inclosed, made and presented by the late 

 General Gordon, of the so-called double or usual form, as 

 well as quadruple, sextuple, and others, besides seeds 

 showing the mode of germination, very fine male spadices, 

 and caA'ed shells. The series of products of Palmyra 

 palm {Bo7-assus flabelliformis) is also a very complete 

 one, comprising sections of the trunk, both longitudinal 

 and transverse, toddy collecting apparatus and various 

 manufactures from the leaves. 



In the Graminece, which was very much crowded 

 throughout, a large increase of space has enabled the 

 interesting collections of maize, sorghums, sugar-cane 

 products, rice, and the numerous grains of India, to be 

 easily examined, while in the Cyperacece the Indian mats 

 from the culms of Cyperiis Pangorei and C. tegetum and 

 other products of the order have been opened out, and 

 now form a striking series. 



APPARA TUS FOR EXPERIMENTS AT A HIGH 

 TEMPERATURE, IN GAS UNDER HIGH 

 PRESSURES 



A DIFFICULTY often experienced in laboratories is 

 how to raise a body to a high temperature while 

 surrounded by a gaseous atmosphere under considerable 

 pressure. 



' Translated frcm La Xatnre, February ii, i883. 



