554 



NATURE 



I ; RY 2, I919 



prov 



■at convenience for water-borne grain traffic, 



which at present is conveyed From Fort William and 

 luii Arthur on Lake Superior to Montreal .-ui Lakes 

 Huron, Erie, ami Ontario. The new route, 1 mb 

 a total distance of 440 miles from the entrance al the 

 mouth of French Rivei in thi citj oi Montreal, will 

 constitute •■ saving of 282 mil's, ["here an- natural!.} 

 546 miles of navigable lake ami river ami 00 miles 

 >ii channel, in which the requisite depth can be ob- 

 tained by dredging, leaving 28 miles only of canal 

 in be constructed. There is a rise of 98 ft. between 

 Georgian Baj ami the summit level at Trout Lake, 

 which will be surmounted by four locks from 21 ft. to 

 29 ft in lift. Succeeding this ihr is a fall of e- ft. 

 in tbe St. Lawrence River, necessitating twenty-three 

 lucks from 5 ft. in 50 ft. in range. The intention is 

 to provide a waterway 22 ft. deep, to accommodate 

 lake boats 600 ft. long, 60 It. beam, and 20 fl. 



draught. Tbe estimated outlay is 100,000,000 dollars, 

 and the work of construction will probably take ten 

 years to complete. The canal project will materially 

 alter tbe regimen of the Ottawa River, which forms 

 the major portion of the route. At present il is a 

 series of deep and wide basins, connected b\ narrow 

 passages, which are broken by falls and heavy rapids. 

 For the purpose of lockage, tbe falls are to be con- 

 centrated and all tbe small rapids eliminated. The 

 forty-five dams required for tbe regulation of naviga- 

 tion (eighteen are of considerable size) will serve to 

 concentrate the water-power at certain points, and it 

 is computed that nearly a million horse-power will 

 thereby become available, though possibly not more 

 than 150,000 h.p. at minimum flow could be developed 

 under existing conditions. 



Tin-: "Wellcome Photographic Exposure Record 

 and Diary" for 1919 is issued by Messrs. Bur- 

 roughs' Wellcome and Co. as usual. Those who are 

 in tbe habit of using this pocket-book will probably 

 be surprised In find that the exposure calculator is 

 improved, so that when set it shows the exposure 

 required fur all tbe ordinary apertures of lenses instead 

 of one only, and that this is facilitated by printing 

 the figures in different colours. The diary, tbe space 

 for classified exposures, and the pages for notes and 

 memoranda remain as before, while tbe tables of the 

 sensitiveness of the various plates and papers on the 

 market and the general information on photographic 

 procedure are brought up to date. The book is a 

 model of compactness and usefulness. 



OUR ASTRONOMICAL COLUMN. 



Schorr's Comet. — The following continuation of 

 the ephemeris of this comet, for Greenwich midnight, 

 is from the elements given in Nature for Decem- 

 ber iq, 1918 : — 



R.A. N. Decl. Log r Log .1 



Magnitude 15. 

 The following observations have been received : — 



G.M.T. RA. N. Decl. Observer Observatory 



b. m. s. , „ 



Nov. 29-8297 4 7 37'6 11 47 47 Burton Washington 



(Naval) 

 30-6602 47 42 11 49 47 ,, „ ,, 



30-7466 4 6 59-5 11 49 56 Barnard Yerkes 



NO. 25H6, VOL. I02] 



1 ^ 's C< »mi 1 th imet was obs< 

 Mis. Freeman with a 3-in. telescope on December 23. 

 h is now grow ing taint. 1 , but 

 until the end of January : 



Ephema is foi Gn eniuh h i/mV 



R.A. N. Decl. I..u r I 



Jan. 5 



t) 41 18 



o 36 45 



13 •■• & 3 2 34 



17 ... 6 29 43 



21 ... 6 27 27 



25 ... 6 26 38 



2y ... 6 26 50 



"Tin-: Companion to 1111. Observatory, 1919." 

 Ibis useful work of referenci is similai in foru 



recent issues. In addition to a summary of data 

 from the Nautical Almanac, it contains Mr. Denning's 

 list of meteor radiants fur every night of the year, 

 ami ephemerides ol variable -i;u- classified into fivi 

 types (Long Period, Algol, (i Lyr;e, ('luster, and 

 Cepheid). I'lic pages mi duuble stars an- dm 



Mr. Jonckheere; he gives recent observations of 



128 pairs and ephemerides for 44. Then are several 

 tables ul astronomical constants. The magnetic 

 elements for Greenwich direct our attention to the 

 increase in the rate of change in the westerly declina- 

 tion. It is now diminishing al tbe rati of 1° in six 

 years, and should reach /em about tin Mid of tbe 

 century. 



A misprint on p. 7 may be noted. The dates of 

 planetary quadrature and station are all printed a line 

 too high, opposite the wrong planet's name. 



Redetermination of the Orbit or 50S Achilles. — 

 Mine. Julie M. Vinter Hinsen undertook the rediscus- 

 sion of the observations of this number of the Trojan 

 group made during the decade succeeding its dis- 

 covery in 1906 (Copenhagen Observatory Publications, 

 No. 29). Some trouble was caused b the fact that 

 the object observed in October, 19 14, proved not to be 

 identical with Achilles. Omitting this, all tbe remain- 

 ing normal places could be satisfied with no errors 

 exceeding b". The following is the final orl 

 Epoch and Osculation 1907 May 28 Berlin Mean Noon. 

 M= 84 3' 1 '9" 

 a = 125° 36' 22-4" 'I 



&=3'5°35 58'5" -i9'°"° 

 i = 10' 18' 13-7' ) 

 <f> = 8° 36' 13-1" 



M =295'9°333" 

 log ^ = 0719179 



THE MANCHESTER LXHIBITION OF 

 BRITISH SCIENCE PRODUCTS. 



ON Thursday, December 26, there was opened 

 without ceremony, in the Municipal Lull. 

 Technology, Manchester, a replica of the British 

 Scientific Products Exhibition held in August and 

 September last in King's College, London, under the 

 auspices of the British Science Guild. The London 

 exhibition attracted much attention and commanded 

 a large attendance of the public interested in the pro- 

 gress of applied science in the United Kingdom, 

 especially as a result of tbe circumstances induced by 

 the war. It proved that much had been accomplished 

 despite unfavourable conditions as to the supply of 

 certain products, some of them of prime importance, 

 inasmuch as they rank as "kej " products upon which 

 certain great industries depend fur their successful 

 prosecution. 



L was felt that the exhibition should bi brought 







