234 



A\^ TURE 



[January 3, 189 = 



consislency uf the measured velocilies of stars when due allow- 

 ance is made for the varying effect of the earth's movement. 

 Dr. Belopolsky, however, has recently suggested a method 

 (Aitr. Nice. No. 3267^ of demonstrating the principle by a 

 laboratory experiment. Imagine two cylinders with axes 

 parallel, on which are arranged vertically two sets of small 

 coirrors, .2, /, . . . ., in, 11, o . . . The mirrors are inclined 

 so thai a ray of light falling on ,; is relltcled to m, back again 

 to l>, then to »/, and so on, finally being directed to the slit of 

 the spectroscope. If now the cylinders be set in rapid rota- 

 tion, in opposite directions, the elTects of the mirrors will be to 

 accelerate or retard the velocity of the ray of light accorditig to 

 the directions of movement. Figures are given which indicate 

 that measurable displacements may be obtained by employing 

 cylinders of from 025 to 07 m. diameter, with ten or twenty 

 mirrors, making from eighty to twenty revolutions per second. 

 With cylinders half a metre in diameter, making eighty revolu- 

 tions per second, and having twenty minors, the equivalent of 

 a velocity of five kilometres per second in the line of sight is 

 obtained, and with modem instruments there would be no dit'li- 

 cnlty in observing the eft'ects of such a movement. It is pointtd 

 out that dynamos already make from seventy to eighty revolu- 

 tions per second, and if sufficient care be taken in the construc- 

 ;ion of the cylinders, the experiment does not seem to present 

 in.-uperable difhculiies. 



" The .\STROPHVSiCAi. Journal." This is the title under 

 which Astronomy and Aitro-Phyiici will appear in future. The 

 University of Chicago has purchased that journal, and arrange- 

 ments have been made to carry it on under the editorship of 

 Profs. Hale and Keeler, assi.-ted by Profs. .\mes, Campbell, 

 Crew, Flos', and Wadsworih, anda number of associate editors, 

 five of whom represent Germany, Great Biitain, France, Italy, 

 and Sweden. The scope of the new publication will be quite 

 as broad as that of Aslronotny and A>tto-Fliyiics, for all 

 problems and investigations of modern physical astronomy will 

 be dealt with. The journal will, in fact, represent the common 

 ground of physics and astronomy, and it should therefore be 

 appreciated ly the ph5sici^t as much as by the astronomer. 

 Workers in astronomical physics should be gratified that their 

 science has progressed sufficiently to need a special organ m be 

 devoted to its interests. Fcftilar As/roiumy will be continued 

 as heretofore, and will appeal to all amateurs, teachers and 

 students of astronomy, and others interested in celestial science. 

 This journal will be practically the old Sii/ciail Afescii^-ci\ and 

 the Aj!ivf!:yiica.' joiiriial \\\\\ he the realisation of Prof. Hale's 

 original plan of a periodical for workers in the domain of the 

 new astronomy. 



Elliptical Oriuts. — A little pamphlet on elliptical orbits, 

 by Mr. H. Larkin, has been published by Mr. Fisher Unwin 

 If it should induce any student o( astronomy to ronstruct for 

 himself the curves in which the apparent 01 bit of a binary star, 

 as we see it, may be resolved, it «ill serve one useful purpose, 

 and probably ihe only one. Fur it is to he hoped that the same 

 student will not embrace the theory of lotmalion of binary stars 

 as given here, wherein they are made to result Iroui the explo- 

 sion of one larger star. There are manyothtr strange things 

 taught, of which Newton never dreamed, and which no one 

 capable '^f reading Newton would ever have slated. Perhaps 

 the most singular is the suggestion of " precarious equilibrium " 

 that would accompany motion in a circular orbit. " Precarious 

 equilibrium " is a curious term, but the context seems to sug- 

 gest that some catastrophe or disaster would result from such a 

 condition. The auihor does not seem to have realised that 

 there is no sudden and violent change between an ellipse of 

 small eccentricity and a circle, and that in the solar system 

 there are instances in uhich the eccentticiiy (if existing) is so 

 slight th,'\t the motion can be conveniently considered as 

 circular. 



rOKESTRV J.\ NATAL} 



"^ATAL lies between Inlitude 28 and 31' S. The climate 

 ''' of the coast i< almost Iropiml, owing to a waim current 

 from Ihe equator. Mangrove dees g-ow along the coast, and 

 sugarcane and tropical Indian fruit ireeii are cultivated there. 

 The land ascends rapidly inland, and the capital, Pieter- 



'I' ' l>t Sir Ditliich llrandi-, KC.I.E., F.K.S., in tlia 



Fen 



S'K 1314, VOL. 51] 



Marilzburg — or Maritzburg, as it is usu.ally called, at fifty miles 

 from the co.ist — is at 2275 feet above sea-level, and possesses an 

 appreciably mild climate. 



The colony is bordered on the west by the Kathlamba or 

 Drakcnsberg, a mountain chain attaining altitudes which exceed 

 9600 feet, and separating Natal from the Transvaal, the Orange 

 Free State, and Basuloland. These mountains form the 

 eastern boundary of the high South .\frioan plateau, which is 

 drained by the Orange River and its tributaries. 



Natal is scantily populated, containing 18,755 square 

 miles, with 532,000 inhabitants, of wliom 38,000 only are 

 Europeans. Most of the latter are English who came by sea 

 and founded Port Durban, but a few are descended from the 

 Dutch Boers who came from the west in 183S-42 and founded 

 Marilzburg. Natal has been an English colony since 1843, 

 when the territory only included 3000 native inhabitants, but 

 their numbers rose rapidly to 100,000 in 1S45, and to 400,000 

 in 1SS3. They are mostly Zulus in the north, and Kaffirs in the 

 south of the colony. 



Much greater progress could have been made in Natal, in 

 trade, agriculture, and manufactures, if it had been connected 

 by roads and railways with the Transvaal and Orange States. 

 The Cape railway, 65omiles long, from CapeTown to Kimber 

 ley, with express trains doing the distance in thirty-six hours, ha^ 

 long been constructed, and in 1S93 this raihv.ay was extended 

 (0 the Transvaal gold mines at Johannesberg. 



In iSSo a railway was constructed from Durban to Maritz- 

 burg, but only recently has it been pushed further inland, and it 

 now reaches the confines of the'colony. Its further extension to 

 Johannesburg is most important for the future prosperity ol 

 Natal. About one and a half years ago a railway was made 

 from Ladysmith in Natal to Harrismith in the Or.ange State. 

 Natal is at present short of funds, and this may partly explain 

 why, having made a good start in forest conservancy, the Colonial 

 Government has not had the resolution to persevere in it. 



The Cape Colony has had for some time a good foresi 

 administration which was organi.sed by a French forest 

 ofiicer, Count Vasselot de Regne-, Conservator of Forests in 

 Algiers, and Mr. D. E. Ilutchins is now Chief Conservati 1 

 of Forests at Cape Town. He was trained at Nancy for the 

 Indian forest service, and left it for seiv'ce at the Cape in 1SS3. 

 Mr. Fourcade, of the Cape forest service, was employed in Natal 

 for nine months in 1SS9, and has written a very valuable paper 

 on the N.-iial foresis, but he declined to quit the Cape service 

 permanently for that of Natal, and was succeeded in 1891 as 

 chief forest oflicer there by Mr. Schopllin, a liaden forest 

 ofiicer. 



The work he undertook of organising a forest deparlmeat 

 in Nal.al W.-IS full of difficulty, especially as the forest revenues 

 weic not expected to cover the expendiuire for a number of 

 years. Irrespectively of the continual clearance of forests for 

 the extension of agriculture, forest fires, unregulated gr.n/.ing, 

 and wasteful limber felling have so cxhausled ilie Natal forests 

 that the aieas still covered with brushwood and forest are widely 

 >caticrcil over the country, and only a small percentage of thetn 

 is still Siaic property. 



From the coast to altitudes of about 975 feel, with an average 

 annual temperature of 67-71", the forest consists of numerous 

 species belonging to the tropical flora. The woods are not 

 more than 30 60 feet high, but something might be made of 

 them, as several species yield valuable timber. Unfortunately 

 nearly all the coast forests are now privale property. 



In a central /one ranging in allituile between 980 and 34SO 

 feet with an average annual temperature of 59°- 67' F., exten- 

 sive tracts are covered with so-called mimosa scrub, formed of 

 seveial species of Acacia : these woods are very thinly stocked, 

 and contain a tall grass undergrowth. The acacias bear plenty 

 of seed, and young growth exists, but is continually being 

 destroyed by the annual grass fires. If only protection could 

 be afforded to these forests against fire, as has been done for 

 the last thiriy years in British India, they could be worked 

 prclilably with short ro'ations — twcniyfour years, according to 

 Mr. I'ourcadc ; it is, however, probable that most of this area 

 will be cleared for agriculture. 



The present aica of the coast and acacia forests is estimated 

 at 196,000 acres of Suite forest, and 1,645,000 acres in priv.ite 

 hands. 



In the higher zone, from 3450 feet up to 9600 feel, with 

 temperate climate, and an average annual temperature "i 

 52-59 , the most valuable foresis arc situated, but Ihey are 



