44 



NATURE 



{May 12, 1887 



taken, from 4 to 8 inches diameter. The number of photographs 

 of the sun obtained during the year was therefore only 92. 



The Transit of Venus in 1882. — Mr. Stone's Report 

 exhibiting the results deduced from the British observations of 

 the transit of Venus in December 1882 has been published. 

 The resulting 'values for the sun's mean equatorial horizontal 

 parallax from the different phases of the transit, are as 

 follow : — 



External contact at ingress it = 8760 ± 01 22 

 Internal „ „ „ t = 8-823 ± 0-023 

 ,, ,, ,, egress tt = 8-827 ± 0-050 (a) 



„ „ T = 8-882 ± 0-043 ()8) 



(a) or {$) are the values resulting from this phase according to 

 the phenomenon selected to represent true contact. The mean 

 of these gives for 



Internal contact at egress ir = 8-855 ^ 0-036 

 External ,, ,, ,, tt = 8*953 ± O'^A^ 



The combination of the values deduced from the internal 

 contacts at ingress and egress gives ir = 8" -839 ± o"-02i or 

 TT = 8" -825 ± o"-028 according as (o) or {$) is used. In the 

 mean from internal contacts ir = 8" -83 2 ± o"-024. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1887 MAY 15-21. 



/"PJ*OR the reckoning of time the civil day, commencing at 

 ^■^ Greenwich mean midnight, counting the hours on to 24, 

 is here employed.) 



At Greenwich on May 15. 

 Sun rises, 4h. lom. ; souths, iih. 56m. 8- is. ; sets, igh. 42m. ; 



decl. on meridian, 18° 51' N. : Sidereal Time at Sunset, 



iih. 15m. 

 Moon (one day after Last Quarter) rises, ih. 35m. ; souths, 



6h. 34m. ; sets, iih. 40m. ; decl. on meridian, 12° 20' S. 



Planet. 



Rises. 



Souths. 



Sets. Decl. on meridian. 



13 33 N. 

 25 29 N. 

 17 33 N. 

 9 27 S. 

 22 13 N. 

 * Indicates that the setting is that of the following morning. 



Occultation of Star by the Moon (visible at Greenwich). 



Corresponding 

 angles from ver- 

 tex to right for 

 inverted image. 



o o 

 ... 63 260 



Reap. 



h. m. 

 3 SO 



May 20. 

 „ 19. 



h. m. 



2 38 w 



17, M 



17, 20 28 m 



15, o 16 m 



19, 2 



16, 



21, 



18, 

 19, 23 



., 17, 



,, 20, 



^sifnifies maximum ; m minimum ; m^ secondary minimum. 



Meteor-Showers. 

 R.A. Decl. 



o m^ 

 m 

 M 

 M 



o m 



oM 

 M 



oM 



REMARKABLE HAILSTONES. 



TV/TR. E. J. LOWE writes to us from Shirenewton Hall, 

 ■^ Chepstow, that remarkable hailstones fell there on April 5 

 from I 55 p m. till 2 p.m. They were far apart, and fell with 

 but little force, and were entirely opaque, and had a vertical 

 cleavage. Some were conical, with an irregular base ; some 

 were spiked at the apex, and of these no two were alike ; others 

 were very irregular in form. A great number were composed 

 of two or three united ; in one case as many as five were fast 

 together. The longest were four-tenths of an inch long, and 

 three-tenths of an inch broad. They melted very slowly, lasting 

 as much as two minutes. The temperature was 39°*5, wet bulb 

 35°-4, and temperature on grass 36°-7. The hailstones were 

 quite different from anything that Mr. Lowe had ever seen. 

 The accompanying figure records a few of them. 



Another account of remarkable hailstones has been sent to us 

 by Mr. Reginald G. Durrant, of Marlborough College : — 



"On April 24, about 12.30," Mr. Durrant writes, "while 

 walking between Melrose and Kelso, a friend and myself were 

 overtaken by a sudden and very violent hailstorm, accompanied 

 by thunder. The violent burst lasted about two minutes, in 

 which time the ground was completely covered with large hail- 

 stones rather more than half an inch long. I say ' long ' ad- 

 visedly, for all the specimens I examined were conical, and were 

 all of them formed in the same way. The points had all the 

 appearance of snow, being softer than the main bulk of the 

 'stones.' These snow portions occupied about one-third of the 

 whole length, being white and non-transparent. The main 

 portions of the hailstones were hard and ice-like, stranded 

 lengthwise with from forty to fifty fibres of ice — each fibre curved 

 separately at the top — and together forming a curved surface, as 

 of a sphere having the snow point for its centre. Thus — 



Angle A B c of section between 50° and 60°. 



" On melting, the pointed part became translucent, while the 

 other part became more opaque than at first, strands often re- 

 maining for a time, partially separated and curving outwards, as 

 though they had been freed from compression in their lower 

 extremities. Thus — 



" The above appearances might admit of the hypothesis that 

 these hailstones were fragments of radiated crystalline spheres. 



