December, 1906.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



613 



The new transit circle has been in regular use during 

 1905, all transits having been observed with the Repsold 

 travelling wire, without clockwork, but an apparatus has 

 now been supplied by means of which the wire is driven 

 electrically across the field. 



77ie new sidereal clock has now been provided with the 

 air-tight enclosure, in which the air is kept uniformly 

 about 75" K. by means of a thermostat ; the temperature 

 and pressure control are now regarded as perfect. 



Fuhlicaiions. — The printing of the Cape Catalogue of 

 8,500 Astrographic Standard Stars has been completed, and 

 the MS. of the Cape General Catalogue for 1900, including 

 4.300 Stars, has been passed for press. 



Victoria Telescope. — The spectroscope h;is been under re- 

 pair during a considerable period, and the telescope used 

 for photography of star clusters, nebula, and the photo- 

 graphic observations of the satellites of Saturn and Uranus. 

 Fifty-four negatives of stellar spectra have been measured 

 and reduced for motion in the line of sight. 



100-inch Mirror for Mount Wilson 

 Observatory. 



Just as the astronomical world is awaiting with special 

 interest the account of the nerlorniance of the new 60-inch 

 mirror made by Professor Ritchey, the munificence of Mr. 

 J. D. Hooker, of Los Angeles, has enabled Professor Hale to 

 arrange for the construction of a still larger reflector. This 

 is to be 100 inches (2.54 m.) in diameter, and 13 inches 

 (33 cm.) thick. The focal length is to be about 50 feet. 

 The disc of glass will in all probability be furnished by the 

 Plate Glass Company of St. (jobain, and the grinding and 

 subsequent optical finishing will be done by Professor 

 Ritchey at the Solar Observatory. The block of glass will 

 weigh four and a-half tons, and it is estimated that the in- 

 strument may be completed in about four }'ears. It is 

 stated that the method of parabolising which Professor 

 Ritchey has perfected quite eliminates the necessity of any 

 hand work in obtaining the final figure. One of the chief 

 difficulties anticipated is the disturbance caused by tempera- 

 ture changes, but as the instrument will be chiefly for use 

 at night, means will be provided to keep the whole cool 

 during the daytime by refrigerating machinery. Regard- 

 ing the prospective working programme for this new 

 leviathan, there are frequent calls for adequate spectroscopic 

 study of stars beyond the reach, on account of their faint- 

 ness, of existing instruments. Researches on the red stars, 

 photography of small siiiral nebula;, minute study of the 

 structure of the large nebuki.', investigations of stellar 

 specira with high dispersion, will all be greatly advanced by 

 the facilities afforded by the greater light-gathering power. 



Recent New Comets. 



Comet g (1906) . — This was announced by telegram from 

 Kiel. The object was discovered at Copenhagen, on 

 November 10, its position then being : — 



h. m. s. d. h. s. 



K.A. = 9 16 3'3 ) 1906 November 10 17 3'5 



Dccl = + 13' 28' 31" (N).j (Copenhagen Mean Time). 



The daily movement in R..\. was given as 4.2"", and in 

 I)ecl.4 1" 10', from vi-hich it will be seen that the comet was 

 then travelling in a north-easterly direction. 



A later telegram announced that the comet had been ob- 

 served from Vienna on November 11, in the position : 

 b. 1.1. s. 



R.A. = 9 20 9-5 



Decl = + 13° 35' 25" (N). 

 From observations made November 10, 11, 12, and 13, 

 various elements have been computed, a selection of which 

 is given below. 



Er,nMENTS. 



Ephemeris. 

 R.A. 



Decl. 



Comet h (1906). —This was discovered by Metcalf, at 



Taunton, on November 14. 



R.A. = 

 Decl.= 



4 

 16' 



6 



(S). 



) November 14 10 0-4 

 f (Taunton M.T.) 



It was observed later by Hammond (?) at Washington 

 on November 16. 



Ii. m. s. d. li. m. 



R.A. = 44 11-45 ! No%'einber 16 11 38 

 Decl.= -2 46' 55" (S).j (Washington Mean Time.) 



Motion, south-westerly. Position at discovery about half 

 way between 35 and 4 ILridani. 



BOTANICAL. 



By G. Massee. 



The Karroo Vegetation in August. 



Tin; Karroo is a broad, elevated tract of country, situated 

 in Cape Colony, which extends from the Ceres district on 

 the west, to nearly as far as Grahamstown on the east. 

 The altitude varies from about i.Soo to 3,000 feet. It is 

 bounded on the north and south by mountain ranges. The 

 rainfall is small throughout the area, in fact, in some parts 

 a whole year may occasionally pass without rain ; the daily 

 range of temperature is very considerable. These marked 

 climatic conditions are such that the vegetation is of a 

 desert or semi-desert character. 



A characteristic portion of this area, near the tiny village 

 of Matjesfontein, about 200 miles distant from Cape Town, 

 was investigated by W'eiss and Yapp during the month of 

 August. The plain, as far as the eye can reach, is covered 

 with low bush or scrub. At a distance the scrub often 

 appears to be continuous, but a nearer view shows it to be 

 an open one, a considerable amount of bare ground being 

 visible. The shrubs possess many features in common, 

 having, for the most part a rounded outline, are richly 

 branched, and usually possess inrolled, heath-like leaves. 

 The prevailing colour is a dull greyish green. In the dry 

 channels of water-courses, often not more than one 

 inch deep and a foot broad, evidently formed by the rush 

 of water during heavy rains, and also in certain low-lying 

 patches where the rain had soaked into the ground, were 

 observed patches of plants that were absent from neighbour- 

 ing less-favoured and drier situations. Pretty little an- 

 nuals occur under the shelter of larger bushes, etc., flowers 

 and fruits being met with on seedlings only one or two 

 inches in height, and on which the cotyledons are still 

 fresh and green. The adaptation these ephemeral plants 

 exhibit to a dry climate turns on the short duration of their 

 lives, a single shower being sufficient to enable tliem to 

 pass through the whole cycle of their development. 



In comparison with other desert areas, succulent plants, 

 along with bulbous or tuberous plants, form a verj- marked 

 feature of the Karroo. Such plants, whether furnished 

 with fleshy roots, tubers, bulbs, and other subterranean 

 water-storage organs, spring up abundantly after the rains. 

 .Many of the Karroo plants, in common with those of other 

 desert regions, are spiny. .V noticeable feature was the 

 spiral twisting of the leaves of many Liliaceje and allied 

 families. Sometimes each leaf is twisted independently, in 

 other instances all the leaves are twisted or spirally coiled 

 together. The majority of the flowers had a strong, sweet 

 perfume. Probably the great majority of perennial plants, 



