324 



NA TURE 



[September 2, 1922 



adopted at the Institute isolates the unexplained 

 residuals with considerable accuracy, and has already 

 facilitated their reduction to law. The residuals for 

 Newlyn thus obtained, over a period of two months, 

 were shown by Mr. Jolly, of the Ordnance Survey, to 

 be correlated with the local barometric pressure and 

 its gradients in two directions at 7 a.m. on the same 

 day. This work has been modified and extended by 

 Dr. Doodson, who has obtained numerical formula?, 

 depending on meteorological data, which give correc- 

 tions for the predicted heights of high and low water 

 at the Port of Liverpool, and there is a prospect of 

 obtaining such corrections on the previous dav by 

 forecasting the pressure distribution a day ahead. 

 The report closes with the encouraging statement 

 that a thorough understanding of the effects of 

 meteorological changes is now only a matter of 

 continued effort. 



Atlantic Hurricanes. — After a period of relative 

 quietness, Atlantic hurricanes are, with the approach 

 of autumn, likely to become a source of danger to 

 vessels traversing the ocean. Bv the aid of wireless 

 the navigator of the present dav has an immense 

 advantage over those of quite recent times, and 

 reports from other vessels as well as from seaports 

 on both sides of the Atlantic can now be received 

 when at sea and charted. The Monthly Meteorological 

 Chart <>f the North Atlantic for September, in addition 

 to its usual information of interest to the sailor, deals 

 with two Atlantic hurricanes experienced in Sep- 

 tember 1 92 1 . The tracks of these hurricanes appeared 

 in the U.S. Monthly Weather Review, December 1921, 

 and charts for several days which embraced the storms, 

 as well as descriptive matter, are given in the Monthly 

 Weather Review, September 192 1. Detailed experi- 

 ences and observations in the Meteorological Office 

 chart will enable the seaman to see precisely how, 

 when afloat, wireless weather reports may help him. 

 With all the aid he may get, it does not relieve the 

 commander from forming and using his own con- 

 clusions, and a knowledge of meteorology is more 

 than ever of use to him. The back of the September 

 chart gives small weather charts for each morning, 

 showing the weather conditions over a large part of 

 the North Atlantic from September 7 to 16. Practically 

 during the whole of this period there were two cyclones 

 travelling first to the north-westward and recurving 

 later to the north-eastward, and some vessels clearly 

 experienced both storms. A study of the various 

 details will facilitate action being taken when in the 

 neighbourhood of similar storms. 



Monsoons as Rain Makers. — In the U.S. Geo- 

 graphical Review, vol. xii., July 1922, is an artii le 

 by Prof. A. McAdie on monsoon and trade winds as 

 rain makers and desert makers. Naturally there is 

 a large amount of originality in the article, but Prof. 

 McAdie makes it clear that much has been taken 

 from Dr. G. C. Simpson's lecture to the Royal 

 Meteorological Society in March last year. The 

 monsoon is essentially a seasonal wind, and the word 

 is used 111 this sense all the world over, but those 

 like 1 >r. Simpson, who with respect to India discuss 

 it from an Indian standpoint, associate the wind with 

 the rainy season from June to September. Prof. 

 McAdie is more especially concerned with the mon- 

 soonal influence on the Californian coast, where the 

 seasonal winds in the summer fail to produce rain. 

 The heavy fogs along the Californian coast show that 

 the water vapour is present and vet there is no rain, 

 although the air stream must rise at least 2000 

 because it is flowing into a region of much 

 higher temperature and the mountains fail to become 

 rain makers. In a midwinter month in California 

 the mountains often rob the air stream of much of 



NO - 2 757~ vol. 1 10] 



the moisture. Instances are given of two consecutive 

 midwinter months showing very different precipita- 

 tion results. The author states that if the winds can 

 bring rain they can also prevent rain from falling, and 

 can in some cases cause deserts. Although warm 

 moist air may be rising, a strong upper-air current 

 may blow the clouds away and interrupt the process 

 of rain making. At the coming meeting of the 

 British Association at Hull a discussion on monsoons 

 is to be opened by Dr. G. C. Simpson, and some further 

 contributions to the subject may be expected. 



Surveying Instruments. — Messrs. T. Cooke and 

 Sons, Ltd., Buckingham Works, York, have issued a 

 revised Price List of the instruments in their Catalogue 

 No. 256, which includes all the surveying apparatus 

 and instruments in ordinary use among engineers and 

 surveyors. Certain of the less common types of 

 instruments in previous lists have disappeared, and 

 component parts of existing tvpes have been standard- 

 ised so far as possible to cut down production costs. 

 A great variety of well - designed theodolites are 

 described and illustrated, ranging from the simple 

 type of builder's transit to the " geodetic " and the 

 " universal " micrometer instruments, giving direct 

 readings to single seconds of arc. A full range of 

 surveyors' levels is also listed, including the U.S. 

 Coast and Geodetic Survey pattern, which has been 

 specially designed for precision work and affords an 

 exceptionally high degree of accuracy. Details are 

 given of the various types and sizes of spirit bubbles 

 which are manufactured by the firm and can be 

 supplied to any degree of sensitiveness down to one 

 second of arc per 01 inch of run. In addition, a series 

 of instructive notes are given on such subjects as 

 tests of optical properties of telescopes ; the applica- 

 tion of stadia lines to instruments ; diaphragms ; 

 circles and verniers ; methods of observing with 

 micrometer theodolites. Thus the catalogue forms 

 a useful manual of instruments for the surveyor. 



Wireless Receiving Set. — The Metropolitan 

 Vickers Co., Ltd., is putting on -the market a com- 

 pactly arranged crystal receiving set specially de- 

 signed for use with the broadcasting services that 

 are soon likely to be started in this country. The 

 set, which is intended for a range of about 15 miles, 

 is priced at 4/. 10s., and consists of a tuner and 

 crystal detector in a case, with a space to hold the 

 head telephone set when not in use ; the set requires 

 only to be connected to the aerial, for the construc- 

 tion of which materials are supplied with the outfit. 

 It is not clear whether the battery is contained in 

 the case, but with this class of apparatus one or two 

 cells only would be necessary. The tuner is con- 

 veniently arranged for working by a handle moving 

 over a dial, and has no rubbing contacts, being formed 

 by two coils, the relative angular position of which can 

 be varied. For greater changes of wave-length, alter- 

 native condensers can be cut in and out. The 

 crystals are chosen with great care, and a spare crystal 

 is provided with each set. The company is also 

 placing on the market a valve set at 23/. 105., includ- 

 ing batteries, aerial, insulators, etc. This is designed 

 for ranges up to 50 miles and employs two valves, 

 one detecting and the other amplifying. The bat- 

 teries are contained in a separate box, and the whole 

 of the leads for the telephone head set and the high- 

 tension and low-tension batteries are brought to one 

 plug, which can easily be detached from the set before 

 the lid is closed. This automatically throws the valves 

 out of operation. A loud-speaking telephone can be 

 substituted for the ordinary head set at a slight extra 

 cost. Both these sets will pick up wave-lengths from 

 300 to 600 metres, and we are informed that both have 

 been approved by the Postmaster-General. 



