114 



SCIENCE. 



[Vol. XIV. No. 341 



SCIENCE: 



A WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES. 



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NEW YORK, August i6, i8 



No. 341. 



CONTENTS: 



The Moscrop Continuous Re- 



CORDEK 105 



An Improved Air-Engine 107 



Production of Essence of Lemon 



IN Sicily 108 



Artificial Silk 109 



Tenth Convention of the Na- 

 tional Electric-Light Associa- 

 tion no 



Health Matters. 

 Disinfection of Springs, and Number 



of Germs in Ground- Water in 



Phthisis in Armies in 



A Good Word for the Gypsies m 



The Utilization of Garbage in 



Cremation in France in 



Pasteur Institute in 



Notes and News : 



Editorial ] 



The World's Fair. 

 The United States, their Growth 

 IN Population in Two Hundred 

 Years. M. C. Meigs : 



Bacteria in Milk and its Products : 

 Book-Reviews. 

 The Ice Age in North America 



IV. M. D. : 

 An Elementary Treatise on Me- 

 chanics 



Steam Engine Design . . . 

 Among the Publishers. 



The APPOINTMENTS BY THE MAYOR to the committee of one 

 hundred on the world's fair of 1892 in New York give very general 

 satisfaction. Fifty-seven industries are represented, and in addi- 

 tion the mayor has named forty-three substantial citizens to fill out 

 the number. Among those specially representing industries, we 

 note, for artists and art collectors, Henry G. Marquand ; architects, 

 Richard M. Hunt ; banks and bankers, Levi P. Morton ; clocks and 

 watches, Daniel F. Appleton ; mechanical engineers, Henry R. 

 Towne ; civil engineers, John Bogart ; periodicals and publishers, 

 John Foord ; printing, J. J. Little ; railroads, Chauncey M. Depew ; 

 scientific and educational interests, Charles F. Chandler. The 

 members of the committee of one hundred have been duly ap- 

 portioned among the four committees on permanent organization, 

 finance, legislation, and site and buildings. As many of the mem- 

 bers of these committees are out of town, no meeting will be held 

 this week. On Tuesday of next week, however, at 3.30 p.m., the 

 •committee on finance will meet in the governor's room in the City 

 Hall ; and on the following Thursday, at the same hour and place, 

 the committee on site and buildings. The other two committees 

 will not be called upon to act until these two have met. After a 

 site has been selected, the committee on legislation will prepare a 

 bill to be presented to the Legislature. 



There is naturally some desire on the part of the smaller cities, 

 more especially Chicago, that the exhibition, or some part of it, 

 should be held within their limits ; Boston, for instance, asking 

 only a branch show specially devoted to New England. There is 

 no likelihood of any splitting of the show into local exhibitions, and 

 the site for the whole will depend, except in so far as political in- 

 fluences may warp things, on the commercial interests at stake. 

 As the time has come when world's fairs pay their expenses if 

 skilfully managed, there is no longer need of a call for any sacrifice 

 on the part of those who will pledge themselves for the expenses. 

 This needed guaranty of funds can be secured in this city just as 

 soon as it shall appear wise to ask it; the question now agitating 

 those having the financial matters in charge being as to how far 

 the money shall be raised by popular subscription to boads of 

 small denomination, the better to enlist popular interest. If any 

 city except Washington should ask for government aid, it is to be 

 supposed that this of itself would rule that city out of the race, the 

 winner in which will be decided by Congress. 



Washington not being a commercial city, it seems undesirable 

 that the exhibition should be held there, especially as there are 

 lacking the facilities for handling the large shipments of goods 

 and the number of visitors. At the same time, the hotels of Wash- 

 ington are of low grade, and entirely unequal to the demands of 

 a world's fair. Then, again, the weather in Washington is likely 

 to be much more oppressive in summer than in New York. The 

 great objection to New York that has been brought forward so 

 far is the lack of local pride. This lack, as is well pointed out in 

 The Evening- Post, is due, to the fact that New York is facile 

 princeps among American cities : it is only the little man and the 

 little town that have to boast continually of such good as they may 

 possess, in order that they may not be ignored, and that have to 

 strive constantly to make their good points the better. New 

 York certainly lacks this spur ; but she is made up of shrewd 

 business-men, who are amply able to carry through a world's fair 

 just as soon as they have decided that their interests demand it. 



THE UNITED STATES, THEIR GROWTH IN POPULA- 

 TION IN TWO HUNDRED YEARS. 



In 1798, eight years after the first census of the United States 

 was taken, Malthus, in England, published his " Treatise on the 

 Law of Population," which excited great interest, and brought the 

 author much hostile criticism. In June, 1890, we shall take the 

 eleventh census of the United States, and will know with certainty 

 what has been our increase in a hundred years. We expect to find 

 a population of 67,240,000. Malthus held that population in a wide 

 country, affording plenty of space and producing abundant food, 

 doubled every twenty-five years. Trying his estimate by the re- 

 corded figures of ten decennial census enumerations, we find that 

 he was very nearly correct. 



With the aid of this information, we attempt to discuss the re- 

 sults to date, and to infer something of the progress of the next 

 hundred years. We do not think it rash to infer the work of a 

 century from the known advance during one just expiring. Tak- 

 ing the figures of the past from "Johnson's Cyclopedia," we find 

 the population of the North American Colonies estimated by Ban- 

 croft as follows : — 



