KXO\VLi:i)GI£ 



SeI'TEMBER, 1912. 



this fact, though tlic uiiited petals may form a cylindrical tube 

 with a circular section. 



In reducing the florets to circles, as shown in Figure 330, 

 the result is not in accordance with N.itnre; for if a large 

 sunflower be examined, it will be seen that it is just like a 

 suppressed cone, the florets being arranged in radial curves. 

 corresponding to the secondary spirals on a fir cone ; these 

 curves arc like the ornamentation on the back of a watch, only 

 the curved r.idii are thirty-four and fifty-five respectively, 

 running in opposite directions. These supply the divergence 

 ill in the usual w.iy of the generating spiral. 



Inexactnesses are always liable to occur in crowded 



structures, in consetjuence of the suppression of some; so 

 that the true maxima have usually subordinate ones on either 

 side of them ; but the origin is always spiral and not circular. 

 Of the "three possibilities" the author gives, the first, that 

 "the discal florets m.ay represent phyllotaxis numbers or their 

 doubles " is the only one possible, except multiples of fives ; 

 but these only occur in simpler conditions, as in pentamerous 

 flowers. 



For further details I would refer any reader interested in 

 phyllotaxis to my several papers in the Transactions of the 

 Liiinean Society. 



BOURNEMOUTH. GEORGE HENSLOW. 



REVIEWS. 



ASTKOXOMV. 

 Astrographic Catalogue. 1900-0. Perth Section. Dec. 

 - .W to - 41°. Vol. I.— By W. Ernest Cooke, M.A., 



F.R.A.S. 52 pages. Vol. IV. 72 pages. 12-in.xg:^in. 

 (Perth, Australia: Fred. W. Simpson. I 



We welcome these portions of two volumes, though small, 

 from the Perth Observatory, W. Australia, as being the first 

 that have yet been published concerning any portion of the 

 southern half of the sky, except a small section near the 

 equator from Algiers. We usually associate clear skies with 

 the southern hemisphere ; but, considering that all the eighteen 

 participating observatories started or might have started this 

 survey work in 1892 (the Perth Observatory was only founded 

 in 1896 and agreed to take on the section which was at first 

 allotted to Rio dc Janeiro) we must either modify our opinions 

 or assume that the great delay in making the preliminary 

 results of the survey available for astronomers is solely due 

 to want of energy and proper organization. As we are well 

 ac<iuainted with the various reasons for the delay we can say 

 that the sky has not been the cause ; this might well have been 

 advanced as the cause at three northern observatories, 

 Helsingfors, Greenwich and Oxford, but the last two have 

 alone, of the eighteen, measured and published their portions, 

 about two hundred thousand stars each. 



The two sections with which we arc now concerned contain 

 five thousand six hundred and forty-six and thirteen thousand 

 six hundred and thirty-six star images in —32° zone, R.A. ()'' 

 to 6*^, and IS"" — 0*". The size of the page is that of Greenwich 

 and Oxford, and the general arrangement of the material on 

 the pages closely resembles that adopted at Oxford. The 

 points of difference are, that three instead of five groups of 

 columns are put on a page — we think four would have been 

 best ; that undue space — two wide columns — is given to the 

 magnitudes ; and that instead of making the numbering in 

 sequence for a whole zone it starts with one for each plate ; 

 as there are one hundred and sixty plates in each zone that 

 means there will have to be one hundred and sixty breaks and 

 the same numbers will be repeated one hundred and sixty 

 times- — or at least the first hundred or so — in the same zone. 

 The only distinguishing point in each instance will be the R.A. 

 of the plate centre; so we must use a cumbersome notation. 

 Brevity is what we should aim at. and say a star is 



-i2° R.A. 5" 51"' No. 229 

 instead of 



-32° 5546. 



The non-repetition of the rcsean interval where it changes 

 in y is a source of error in the practical use of the work. 

 There is room for much economy of space or printing ; when 

 a plate ends, the rest of the cohnnn is left blank : the blank 

 space on a page is frequently one quarter to one half of the 

 page. We thought paper .and printing were expensive in 

 Australia. If we take Vol. I, R.A. O'' — 6'', tlic measures occupy 

 thirty-four p.ages of three columns each ; in those pages there 

 is an equivalent of more than nineteen blank columns, thus 

 about twenty per centum of the whole is wasted. Economy 

 might be considered here. We venture to urge that the name 

 of the Observatory, Perth, should be printed on each page, 



as there will be Astrographic Catalogues from seventeen other 

 observatories 1 though we do not expect them all to be available 

 for astronomers' use before 2000. 



In the methods of measurement and reductions, and in the 

 formation and arrangement of the tables for reduction, those 

 brought into use by Professor Turner (OxfordI have been 

 closely followed : it is of the greatest advantage to have some 

 uniformity in this international survey work, though unlimited 

 time and money in igli t produce better results. The magnitudes 

 are designated by letters according to Mr. W. E. Cooke's own 

 scheme, explained on pages 8 and 9 of Vol. I. 



Though we congratulate Mr. Cooke in having set the lead 

 for the southern sections, especially as he started some years 

 later (Algiers work is just the part to the north and south of 

 the equator), we should have preferred even a little more delay 

 and got a complete volume out at a time ; this would save 

 cost in binding and time in distribution ; the numbering might 



have then run on from plate to plate. 



F. A. B. 



Catalogue of 2,()IJ Stars between 35^ and 37' S. Dec. — By 



W. Er.nest Cooke. 122 pages. 12i-in. X 10-in. 



(Fred. W. Simpson.) 



The book before us is the fifth of this series of meridian 

 observations made with the Troughton & Simms six inches 

 in diameter object-glass at the Perth Observatory, West 

 .Australia. 



This volume contains the positions of two thousand and 

 forty-three stars between — 35° and — 37° declination derived 

 from observations made so recently as in the year 1910. This 

 speedy publication of a considerable catalogue of meridian 

 work is highly commendable to Mr. W. E. Cooke and the 

 assistants who contributed the bulk of the work, and is quite 

 contrary to the usual long interval between observations and 

 publication. It is a valuable catalogue for southern astro- 

 nomical photography. 



The primary object of this series of catalogues is to provide 

 good meridian places for those stars upon which to base the 

 corrections of the photographs being taken at Perth for the 

 Astrographic Survey. A minimum of three stars scattered 

 over each sijuare degree is aimed at ; that would aftord twelve 

 to fifteen reference stars on each plate ; being observed nearer 

 the epoch at which the photographs are exposed than is usual, 

 the proper motions have a less disturbing effect. .An average 

 of three observations for each star has been maintained. We 

 notice that the observational work depended upon Mr. H. B. 

 Curlewis for the transits, and Mr. C. Nossiter for the 

 microscope readings ; it is an important point not to have 

 varying observers in meridian work. As (juite fifty per 

 centum of the stars are below the ninth magnitude we 

 do not find th.at any allowance has been made for magnitude- 

 equation ; 9-5 to 10-5 m.agnitudc stars are not easy to observe 

 with a six-inch lens. Was any change made in the method of 

 observing these and the brighter stars ? 



The catalogue itself occupies sixty-four pages ; there are 

 two appendices of fifty-eight pages consisting of blank forms 

 for writing in corrections, as explained in Volume I\"; such 

 are of use at the Perth Observatory, but we do not think 



