30O 



SCIENCK 



[Vol. XIV. No. 352 



SCIENCE: 



A WEEKLY NEWSPAPER OF ALL THE ARTS AND SCIENCES. 



PUBLISHED BY 



N. D. C. HODGES. 



47 Lafayette Place, New York. 



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Vol. XIV. NEW YORK, November i, 1889. No. 352 



CONTENTS: 



The Halpine Toepedo-Boat 291 



American Public Health Associa- 



292 



Electrical News. 



A New Ammeter 294 



Indicating Temperatures at a Dis- 

 tance 295 



Metal Sheets as Electrical Screens. 295 

 Automatic Electric Balance 295 



Health Matters. 



Chloroform as an Ansesthetic 295 



Preventable Blindness 295 



Suggestive Therapeutics 296 



Oxygen Inhalation 296 



Notes and News 296 



Editorial 300 



The United States Hydrographic 

 Office under Lieut. Dyer. ~ 

 World's-Fair Statistics. 



Annual Report of the Hvdrog- 



300 



Book-Reviews. 



Hygiene and Public Health 301 



Alternate-Current Machineiy 301 



A Handbook of Descriptive and 



Practical Astronomy 301 



Chambers's Encyclopaedia 302 



Hints to Travellers, Scientific and 



General 302 



Coal and the Coal Mines 302 



Among the Publishers 302 



Letters to the Editor. 

 Electric Eccentricities 



Geo. Gibso7i ; The Editor 305 

 A Lightning Discharge in Quebec 



y. C. k. La/lamme 305 

 Industrial Notes. 



The Victor Type- Writer 305 



Light in Dark Places 306 



New Electric Railways 306 



The Julien Electric Traction Com- 

 pany 306 



To-day quite an important change takes place in the 

 office of the hydrographer of the Navy Department. Lieut. George 

 L. Dyer, who has occupied that position, vacates the office to per- 

 form a tour of duty at sea in conformity to the usage obtaining in 

 our naval service, which, however efficient an officer may have been 

 in the performance of duty, requires that tours of service on shore 

 must alternate with those afloat. During the time that Lieut. 

 Dyer has been associated with the office, both as principal assist- 

 ant and as hydrographer, numerous changes of great benefit to the 

 naval service have taken place. The establishing of the branch 

 hydrographic offices has proved remarkably successful, and their 

 importance is acknowledged by the maritime community the world 

 over. The issue of the " Pilot Charts " and their supplements was 

 begun, and they have rendered themselves indispensable authorities 

 for all shipping that crosses the Atlantic. The office in Washing- 

 ton has been greatly enlarged, and its facilities for coping with the 

 marvellous increase of work have been greatly improved. The 

 assumption of the collection of meteorological data from the mer- 

 chant marine, the improvement in the office publications, and the 

 establishment on a permanent basis of the division of marine 

 meteorology, are all matters of the greatest benefit and importance, 

 and bear the impress of the ability of the officer controlling them. 

 The matter of the use of oil at sea and the dissemination of data 

 collected in relation thereto among seafaring people has probably 



received as much of the personal attention of Lieut. Dyer as any 

 other important feature of his regime; and he leaves his office with 

 the satisfaction of knowing that his efforts in the great cause of 

 humanity have been the means of saving hundreds of lives and much 

 property, the value of which can hardly be estimated. We take 

 pleasure in wishing Lieut. Dyer an enjoyable cruise, with the hope 

 that his pouring oil upon the troubled waters for the sake of others 

 may result in his having smooth seas and safe voyages wherever 

 duty may call him. 



As THE DISCUSSION of a possible world's fair somewhere on 

 this continent in 1892 is now going on, a study of the results of the 

 Paris Exposition is in order. Any such exhibition brings to the 

 city in which it is located a great accession of transient population, 

 with a resulting strain upon the resources of that city in its facili- 

 ties for transporting, housing, and feeding. Every stranger, when 

 he reaches Paris, is recorded by the police ; every pound of food 

 and pint of drink that enters the city gates is taxed ; the railways 

 make prompt and detailed returns of their business ; the theatres 

 make returns ; and in various ways the facts that show how a great 

 city is affected by these crowds of strangers are better known in Paris 

 than they could be in any American or English city. Such of these 

 statistics as have been published show that the total number of 

 visitors, or visits, will .exceed 24,000,000. The maximum attend- 

 ance so far was on Sunday, Oct. 13, when 402,000 were recorded. 

 This may, however, be exceeded, as the attendance shows a ten- 

 dency to increase as the closing day, Nov. 6, draws nearer ; the 

 fall in the price of tickets, which has been very great, doubtless 

 having its effect as well. Up to Sept. 30, the attendance recorded 

 at the gates was 19,405,701, and the daily average had been 130,- 

 000. The daily averages at previous exhibitions have been, at 

 London, 1851,40,000; Paris, 1855,24,000; London, 1862, 34,000 ; 

 Paris, 1867, 42,000; Vienna, 1873, 40,000; Philadelphia, 1876, 

 61,000 ; and Paris, 1878, 70,000 : so that the average daily attend- 

 ance of the exhibition about to close has been nearly double that 

 at the last held in Paris, which was the largest up to that time. 

 The transportation statistics are too imperfect yet to be of much 

 interest, the greater portion of the travel of the railways coming as 

 late as August, for which month the returns are not available. 

 Still we find that in May, June, and July, 10,704,703 persons ar- 

 rived in Paris in 1889, against 9,647,289 in 1888, an increase of 

 1,057,414; and in the same period 10,782,766 left, against 9,562,019 

 in 1888, an increase of 1,220.747. There were, on the average, 

 25,000 more passengers passed through the principal Paris stations 

 each day during these months than in the corresponding months 

 of 1888. It is estimated that 120,000 Americans flocked to the 

 exhibition. Of the patronage of the hotels it can be said that they 

 received more than twice as many guests in the three months for 

 which we have figures as in 1888. That Paris consumed more 

 food during the exhibition cannot be doubted, but it is strange to 

 have to record a falling-off in the consumption of beef when so 

 many supposed beef-eaters were added to the population. Nor 

 did these visitors show any inclination to feast on horses or don- 

 keys, two items of food which showed only the normal increase of 

 late years. The theatre-owners, and the proprietors of places of 

 amusement in general, feared that the exhibition might prove a 

 damaging rival. The tax returns show just the opposite, being 

 more than double those in the previous year. 



ANNUAL REPORT OF THE HYDROGRAPHER. 



The annual report of the hydrographer of the Navy Department 

 contains much of great value to the maritime community, and gives 

 a most comprehensive review of many of the important changes 

 that have taken place in that office during the period that Lieut. 

 Dyer, the outgoing hydrographer, has been connected with it. 



The necessity for an earnest co-operation with the Army Signal 

 Service is particularly dwelt upon, and it is clearly shown what 



