142 



SCIENCE. 



[Vol. VIII., No. 184 



— The 'Pacific coast tide tables' for 1887 have 

 "been received from the printer by the coast sur- 

 vey. It is a curious fact that these are the most 

 perfect ever yet received, and close examination 

 thus far reveals not a single en-or or misprint in 

 the entire edition. The ' Atlantic coast tide tables ' 

 will be given to the public in about a week. Sec- 

 tion xvi. of the topographical survey of the District 

 of Columbia is in the hands of the photo-hthog- 

 rapher. This beautiful sheet covers the country 

 in the vicinity of the picturesque village of Ten- 

 allytown, near which the summer house of Pres- 

 ident Cleveland. is located. The chart of Puget 

 Sound, the Gulf of Georgia, Straits of Fuca, etc., 

 in one sheet, will probably be placed in the hands 

 of agents within two weeks. This chart will sup- 

 ply a long felt want to the people of Washington 

 Territory, covering, as it does, all the inland 

 waters from Gray's Harbor, on the Pacific coast, 

 to the Nanaimo coal fields, in British Columbia. 

 Assistant Schott is well advanced with the com- 

 putation of magnetic observations of the Greely 

 party in the Arctic regions ; the computations of 

 Arctic tides from observations made by the same 

 explorer are also well under way, 



— The annual exportation of ivory from Africa 

 has of late years been nearly four hundred thou- 

 sand pounds, aboiit two-thirds of which is ob- 

 tained from tlie eastern part of the continent. 

 These figures represent a sum of about four mil- 

 lion dollars, and the death of sixty-five thousand 

 elephants. 



— The fiftieth anniversary of the founding of 

 South Australia in December, 1836, will be cele- 

 brated by an international exposition to be opened 

 on the twentieth of June next at Adelaide. The 

 population of the colony now numbers three 

 hundred and thu-teen thousand, but at present it 

 is decreasing rather than increasing. 



— Computations from statistics show about one 

 million as the number of blind persons tlu-ough- 

 out the world, which, estimating the population 

 of the globe at 1,400,000,000, gives about one blind 

 person to every fourteen hundred. In Austria 

 there is one to every 1,785 inhabitants ; in Sweden, 

 one to every 1,418 ; in France one to every 1,191 ; 

 in Prussia, one to every 1,111 ; in England, one to 

 every 1,037, etc. The greatest proportion of blind 

 persons is in Egypt, where, in Cairo, there is one 

 among every twenty inhabitants. Austraha shows 

 the greatest variation ; in New Zealand there is 

 only one to every 3,550 inhabitants, while in Tas- 

 mania there is one to every 625. The nation 

 possessing the greatest number of institutes for 

 the blind is Germany with thirty-five ; next comes 

 England with sixteen ; France with thirteen ; 



Austria-Hungary with ten ; Italy with nine ; Bel-' 

 gium with six ; while according to our authority, 

 the Deutsche rundschmt fur geographie und sta- 

 tistik, America, Asia, and Africa together possess 

 only six. There are two in Australia. 



— There are twenty-one cities in the German 

 empu-e containing each more than one hundred 

 thousand inhabitants. 



— The population of New South Wales, accord- 

 ing to the census recently taken, is very nearly 

 one million, which is of interest as showing the 

 very rapid growth, forty per cent increase, during 

 the last ten years. 



— According to Dr. Tipton of Alabama, in the 

 Medical journal, the negroes before the war in the 

 south never had phthisis, but now it is the great- 

 est scourge among them. He also says that the 

 negro is rarely if ever near-sighted. 



LETTERS TO THE EDITOR. 



*it* Correspondents are requested to he as brief as possible. The 

 writer's name is in all cases reauired as proof of good faith. 



The source of the Mississippi. 



In June, 1884, the New York Herald announced 

 that recent explorations had revealed the true source 

 of the Mississippi Eiver to be, not the lake discovered 

 by Schoolcraft in 1832 and named by him Itasca, but 

 a tributary lake to the south of it, discovered and 

 first explored by a Capt. Willard Glazier in 1881. 



In commenting upon this alleged discovery, Science 

 says (May 15, 1885): " To this lake he (Glazier) gives 

 his own name, that the fame of his achievement may 

 be perpetuated. It is perhaps unfortunate that, as 

 this whole region was sectionized by the general land 

 office several years previously, lines having been run 

 at every mile, a prior claim to this great discovery 

 may arise." 



This comment was thought to be sufiicient to im- 

 press upon all the absurdity of a claim to have dis- 

 covered, at this late day, a lake of any considerable 

 size in the region referred to ; but as one of our pop- 

 ular school geographies^ has indorsed the genuineness 

 of this discovery (?) by adopting ' Glazier Lake ' as 

 the source of the Mississippi, and as the makers of 

 our school geographies have a bad habit of blindly 

 following each othei-'s lead, it will be well, pei'haps, 

 to examine a little more closely Mr. Glazier's claim 

 to such recognition. 



In 1806 Lieut. Zebiden Pike, and in 1820 Governor 

 Lewis Cass, penetrated to Eed Cedar or Cass Lake : 

 but there is no record of definite explorations beyond 

 this lake earlier than those of Henry R. Schoolcraft, 

 who in 1832, under authority of the war department, 

 led a well-equipped expedition through this region. 

 In his brief official report, dated at Sault Ste. Marie, 

 Sept. 1, 1832, Schoolcraft states that Lieutenant 

 Allen accompanied him as topographer, and that he 

 carefully collected material for maps and plans of 

 the entire route. Upon his return to Detroit, School- 

 craft wrote, in 1833, a full narrative of the expedi- 



1 '■Barnes's complete geography'. By James Montetth. 

 New York and Chicago, A. S. Barnes <& Co. Copyright 



1885. ^^ ^ 



