2 40 



A' .'7 TURE 



[December 24, 1908 



improved telescope triple object-glass : J. W. GifTord. 

 The method and fonnulte for figuring and testing were 

 described and illustrated. 



Royal Meteorological Society, December i5.— Dr. H. R. 

 Mill, president, in the chair. — Some forms of scientific 

 kites : Eric S. Bruce. Some forms of scientific kites 

 were described other than the well-known box-kite in- 

 vented by Mr. Hargrave. This is heavier and more 

 breakable than many other forms of kites, but it possesses 

 the indisputable advantages of stability, ascending steeply 

 and exerting great force. When there is wind enough to 

 fly it, it would appear unsurpassed. It is, however, 

 advisable that meteorological kite ascents should be carried 

 out as continuously as is possible, and that as many as 

 possible of those days when the heavier box-kite will not 

 rise should be utilised for obtaining information. On this 

 account Mr. Bruce considers that lighter forms of kites, 

 which are specially adapted for use in very light winds, 

 would be of great service. He then described the Brogden 

 six-winged bird-kite, the Salmon eighteen-winged kite, the 

 Barclay honeycombed-kite, the Cody bat-winged box-kite, 

 the Balston butterfly-kite, and the Burgoyne aluminium 

 kite. — The registering balloon ascents in the British Isles, 

 July 27 to .August I, 1908: C. J. P. Cave. These ascents 

 were made in connection with the extended series of 

 .ascents of kites and balloons arranged by the International 

 Commission for Scientific .'\eronautics. Some of the 

 records show considerable differences of temperature 

 between the up and the down traces, which seems to 

 indicate that fairly rapid fluctuations of temperature may 

 occur in the upper air. The average height reached was 

 IO-2 miles, the greatest height being 14-3 miles. .Ml the 

 balloons except one reached the isothermal layer, and show 

 that the diminution of temperature with height ceases 

 after a certain point, or that there is a rise of tempera- 

 ture ; the rise of temperature is quire marked, even in 

 the case of balloons which have attained their highest 

 point after sunset, and cannot, therefore, be the effect of 

 solnr radiation. — Balloon observations at Ditcham Park, 

 near Petersfield, July 27 to .'Xugust 2, 1908 : C. J P. 

 Cave. The registering balloons which were sent up were j 

 followed by means of theodolites for the determination of 

 wind velocities at different heights. The balloons were 

 observed until after they had entered the isothermal laver, 

 and in each case there was a well-marked diminution of 

 wind velocity at its lower limit. 



DUBLI.N'. 



Roval Irish Academy. Peren'her T4.— Dr. F. A. 

 Tarli.'lon, president, in the chair. — Extensions of Fourier's 

 and the Bessel-Eourier integral theorems : Prof. \V. McF. 

 Crr. Hankel's fundamental equation is obtained with an 

 extension to functions of any order, real or complex ; the 

 parameter is regarded as complex, the ordinary line in- 

 tegral from zero to infinity being replaced by one taken 

 along a contour in which the limits of the parameter are 

 a positive and a negative infinity. This is done by first 

 obtaining equivalent equations in the K functions, the 

 contour being deformed into one everywhere at infinity; 

 along this each function may be replaced by the domin.i'nt 

 term in its asymptotic expansion, and when this is done 

 the required results follow by Fourier's integral theore;n. 

 Precisely similar theorems are obtained in which the Besscl 

 fimctions are replaced by their derivatives of any, but 

 the same, order. Expansions, are obtained suitable for the 

 discussion of vibratory motion in the space outside a 

 sphere or an infinite cylinder ; for example, an arbitrary 

 function of r is expressed, for values >o, by an integral 

 the element of w-hich is a multiple of 



|I„(A;-)J_„(A«)-J_„(Ar)J„{A,r);a'A. 



The author believes that the investigations are valid for 

 fimctions which satisfy Dirichlet's conditions, and for no 

 others. 



New South Wales. 

 Royal Society. Oc'^ber 7.— Mr. W. M. Hamlel, presi- 

 dent, in the chair. — The influence of infantile mortality 

 on birth-rale: (;. 11. Knibbs. It is shown from the 



statistics of all countries furnishing accurate statistics 

 that : — (i) For any ojic country uniform increments to the 

 rate of infantile mortality tend to produce uniform incre- 

 ments in the birth-rate ; that is to say, the birth-rate /3„, 

 which would correspond to an absence of infantile 

 mortality, is given by the equation j3„ = 5 — t/n, where ^ 

 is the actual birth-rate, y. the rate of infantile mortality, 

 and h a constant peculiar to each community or country. 

 (2) The coeflicicnt showing the influence of inantilc 

 mortality on the birth-rate as actually deduced is in all 

 cases very small. (3) No general law exists for the world 

 as a whole. (4) The constant b does not appear to be 

 influenced by the magnitude of the birth-rate itself, since 

 it is approximately the same for a country with a low 

 birth-rate (such as France) and a high birth-rate (such as 

 the Netherlands). (5) That the a priori tendency of in- 

 crease of birth-rate through increased rate of infantile 

 mortality may be masked by other influences. 



NO. 204,:;, \'OL. 79] 



CONTENTS. p.AGE 



The Anatomy of Dicotyledons. By A. W. H. . . 211 



Problems of the Paper Mill . . ... 212 



The Works of Linnaeus. By B. D. J 213 



Practical Physics. By L. B ... 213 



The Edible Crab . . ... .... 214 



The Ashmolean Natural History Society of Oxford- 

 shire. By L. J. V . . 215 



Electrochemical Practice and Power Development 215 



Some New Chemical Books. By J. B. C 217 



Our Book Shelf: — 



Searle : " Expeiimental Elasticity."— Dr. C. Chree, 



F.R S 218 



"B?auti''ul Flowers and IIow to Grow Them " . . . 218 

 Watson: "The Philosophical Basis of Religion; a 



Series of Lectures " 219 



Hewlett : " A Manual of Bacteriology, Clinical and 



Applied" , 219 



"Ticks" 219 



" Who's Who," 1909 ; " Who's Who Year- Book for 

 igog"; "The Engli.shwnnian's A'ear-Bouk and 

 Directory," igog; "The Writers' and A'tists' 



Year- Book," 1909 220 



Tultle : " Arcana of Nature" 220 



Letters to the Kditor- — 



Flving Machines and their Slabilily. — A. Mallock, 



F.R.S • ... 220 



Zeeman ElTcct in Weak Magnetic Fields — Prof. 



H. Nagaoka 221 



Women and the Chemical Society. — T 221 



Autumn, and After. — Alex. B. MacDowall . . 221 

 The Datwin Commemoration at Cambridge (June 



22-24,1909). By Prof. A. C. Sward. F.R. S. . . . 221 

 Nrw Light on Ancient Egypt. {Ilhislialed.) By 



H. R. Hall 222 



A Pigmentation Survey of Scotland 223 



The New Wireless Telegraph Station. By M. S. . 224 

 Swedish H> drographical and Fishery Investiga- 

 tions. By A. E. H 225 



Notes 226 



Our Astronomical Column : — 



Morcliou^e's Comet, 1908. .....; . ... 231 



Observations of the Surfaces of Jupiter's Principal 



Satellites and of Titan . . ' 232 



Corrections of the Position and Diameter of Mercury . 232 



The South Polar Cap of Mars 232 



The " Companion to the Ob«en-ato!y " 232 



The Nizamiah Observatory at Haidarabad ... . 232 

 Prize Subjects Proposed by the French Academy 



of Sciences for the Year igio 232 

 Chemical Research at the University of Man- 

 chester 233 



Waters and Glaciers. By G. A. J. C. . . 2j3 

 The 1 ransvaal and Indian Departments of Agricul- 

 ture. By Dr. E. J. Russell . . .235 



Who Bu'h the Briiish Stone Circles .' By J. Gray 236 



Th - British Oinitholopists' Union 238 



University and Educaionai Intellige'-c:? . . . 23S 



Societies and Academies 239 



