September 8, 192 1] 



NATURE 



69 



Climatology has contributed largely to the successful 

 introduction of the date-palm, for this tree requires 

 tropical or semi-tropical weather conditions and very 

 little water ; the palms will flourish in what appears 

 to be a sandy desert provided the temperature condi- 

 tions are favourable. About two hundred and fifty 

 Southern Pacific railway station agents also keep tem- 

 perature and precipitation records. The author men- 

 tions that a San Francisco instrument manufacturer 

 has sold more than a thousand rain-gauges, and rain- 

 fall records are readily maintained. 



Technologic Paper No. 192 of the Bureau of 

 Standards, Washington, consists of an account by Dr. 

 G. K. Burgess, of the Bureau, of the tests of six 

 hollow cylindrical steel castings manufactured by the 

 centrifugal process. The castings were 6 ft. long and 

 of diameters up to 18 in., with holes of various dia- 

 meters through them ; they were made with the 

 mould revolving about the axis, at a speed not 

 specified. Samples of the metal taken from different 

 parts of the comp'.ete castings were tested for hard- 

 ness, tensile strength, soundness, structure, and 

 isity, both in the condition as cast and after heat 

 itment of various kinds. It was found that there 

 - a slight segregation of carbon, phosphorus, 

 ■phur, nickel, and copper in the radial direction, 

 none of manganese and silicon. Small blow- 



holes were evident in the inner 1/16 in. of the cast- 

 ings. .\fter heat treatment several of the castings 

 showed mechanical strength equal to forged materials 

 of the same composition, and satisfied the ordnance 

 requirements for gun forgings. Microscopic examina- 

 tion showed no hard spoti;, flaws, or other defects 

 outside the layer 1/16 in. thick at the inner surface, 

 and the process appears to be one of great promise. 



Messrs. Duckworth and Co. include in their 

 autumn list of forthcoming books "The Wheat Plant : 

 A Monograph," by Prof. J. Percival. Part i will 

 deal with the botany of the plant and its various parts, 

 and part 2 with the methods of cultivation of the 

 different varieties, with chapters also on hybridisation, 

 breed, and yield. Another work promised by the 

 same publishers is " The Great W^hite South : Being 

 an Account of Experiences with Captain Scott's 

 South Pole Expedition, and of the Nature Life of the 

 Antarctic," by H. G. Ponting, with an introduction 

 by Lady Scott. 



The Cambridge University Press is bringing out in 

 the autumn for Major Leonard Darwin a small work 

 entitled " Organic Evolution : Outstanding Difficul- 

 ties and Possible Explanations," being a collection of 

 brief notes on biological matters arising from "The 

 Origin of Species." 



Our Astronomical Column. 



The August Meteoric Display. — Another proof of 

 the unusually abundant display of August meteors 

 belonging to the Perseid shower is provided by ob- 

 servations made by Mr. P. Meesters at Halfweg 

 (near Amsterdam-Haarlem), Holland, with an out- 

 ' look from north-west by north to east. 



On August II, watching from 9.15 until 11. 15 



A.M.T., Mr. Meesters counted twenty-eight meteors, 



I viz. 2, 3, 4, 2, I, 5, 7, 4, during each quarter of an 



hour. On .\ugust 11, watching from 9.15 until 10.15 



A.M.T., thirty-nine meteors were seen, viz. 6, 17, 9, 



{ 7. At 9.29 A.M.T., in two seconds, four meteors were 



y seen equal to Venus or Jupiter. Clouds came over 



I the skv at 10.15 A.M.T. From 11.30 until 1.45 



I A.M.T. Mr. Meesters counted 286 meteors, viz. 60, 



i 68, 54, 50, 54, in each quarter of an hour. On 



August 12, watching froni 9.15 until 10.15 A.M.T., he 



i counted 4, 7, 6, i objects in each quarter of an hour ; 



' clouds coming over the sky prevented further ob- 



! serrations. On August 13, from 1.45 until 2 A.M.T., 



j three Perseids were seen between drifting clouds. 



I Several of the Perseids were equal to, or brighter 



I than, stars of the first magnitude. The maximum 



j display was thus in the latter part of the night of 



1 August II. 



j ^ The Bright Object near the Sun. — Two observa- 

 ! tions of this object were made in England on 

 August 7, some hours before that at Mount Hamilton. 

 The first (communicated bv Col. Markwick) was 

 made by Lieut. F. C. Nelson Day and others at 

 Ferndown, Dorset, about 7h. G.M.T. Its magnitude 

 was estimated as minus 2 and its distance from the 

 sun as 4°. 



Mr. S. Fellows obser\ed it at Wolverhampton with 

 binoculars shortlv after sunset (Eng. Mech., August 

 "i\ He noted it as reddish, elongated towards the 



sun, from which it was distant 6°. The estimates 

 of distance are probably too rough to use for the 

 deduction of motion. It may be noted that a comet 

 with retrograde motion near the plane of the ecliptic 

 and small perihelion distance approaching the sun 

 from behind might remain in close proximit\- to it 

 the whole time that it was bright. 



Astr. Nach. No. 51 16 contains full particulars of the 

 luminous bands seen at the Konigstuhl and Sonne- 

 berg Observatories on August 8d. i2h. G.M.T. It 

 appears probable that they were auroral, esjjecially 

 as Prof. M. Wolf noted a similar appearance on 

 August 5, iih. 15m. to iih. 36m. G.M.T. It was "a 

 long, ver\- bright cloud west of the Pleiades, brightest 

 near 8i\rietis ... it faded rapidly, only a trace 

 visible at iih. 36m." 



Minor Planets. — The planet (7) Iris is in opposi- 

 tion this month, and as its magnitude is 72 it is 

 within reach of binoculars. The following ephemeris 

 for Greenwich midnight is by M. Michkovitch (Mar- 

 seilles Circ. No. 512), with corrections of +o-4m., +4', 

 deduced from an .Algiers observation on August 16 : — 



log r 

 Q-295 



0-290 



0286 



log A 



9-993 

 9981 

 9.982 



Perihelion passage will be e^rly in 1922. 



Astr. Nach. No. 5 116 contains the names assigned 

 by Prof. M. Wolf to seventeen planets discovered by 

 him in recent years. Planets 834 and 907 are named 

 respectively Burnhamia and Barnardiana after the 

 two famous American astronomers. 



NO. 2706, VOL. 108] 



