34 



SCIENCE. 



[Vol. XVI. No. 389 



American Geological Society will hold its semi-annual meeting at 

 the State House in Indianapolis on Aug. 19. Professor J. D. 

 Dana, New Haven, Conn., is the president, and Professor J. J. 

 Stevenson, University of the City of New York, secretary. 

 Members of the association arriving in Indianapolis before the 

 meeting should call for information at the temporary office of the 

 local secretary, No. 19J North Pennsylvania Street. A few days 

 before the meeting a local office of information will be established 

 near the railroad-stalion, as will be stated in the circular of the 

 local committee. 



— Professor Artliur Winslow, State geologist of Missouri, in 

 submitting to Gov. Francis a statement setting forth the opera- 

 tions of the State Geological Survey during the month of June, 

 says that during the early portion of the month the results of de- 

 tailed field-work in the coal-fields were reduced, and transferred 

 to the final map. Since this time field-work has been continued, 

 and about twenty square miles have been covered. Paleontologic 

 work has been continued in Pettis County, and has been extended 

 into Lafayette County as far as Odessa. Several hundred pounds 

 of specimens have been collected, and have been shipped to Pro- 

 fessor Williams for study. On June 20 Mr. Erasmus Haworth 

 reported for work, and has been assigned to the south-eastern part 

 of the State, where he is engaged in defining the distribution and 

 relations of the crystalline rocks of that section. Mr. Haworth 

 is professor of geology and mineralogy at Penn College, Oskaloosa, 

 lo. He has worked in the south-eastern portion of the State in 

 past years, and has volunteered his services to the survey during 

 the present summer. In the laboratory the analytical work on 

 the mineral waters collected in April is comi^leted, as well as the 

 calculation of results, and the preparatory notes for a report on 

 the results have been written out. In addition, analyses have 

 been made of forty-seven specimens of limestone from quarries in 

 and about St. Louis, with the object, among others, of determining 

 their qualities for building-purposes, and for the production of 

 lime and cement. Inspections have been made in Cape Girardeau 

 and Stoddard Counties. In Cape Girardeau County clay deposits 

 of promising appearance were visited. The qualities of the clay 

 and the distribution of the deposits deserve determination. In 

 Stoddard County a deposit of brown coal or lignite was visited, 

 near Ardecla, on the Cotton Belt Railway. This coal has been 

 opened up during the past winter by shafts and drifts^ It occurs 

 associated with the clays and sands of Crowley's Eidge. Similar 

 coal is found along the same ridge farther south, in Arkansas. 



— The latest plan for connecting a moving tram-car to an under- 

 ground conductor without a slot in the roadway is that of the 

 Lineff Electric Traction and Lighting Syndicate, of 11 Queen Vic- 

 toria Street, London. According to Engineering, the track con- 

 sists of the usual grooved rails, and a third or contact raU be- 

 tween the others. This is flat-topped, and the surface lies flush 

 with the roadway. It is formed in short lengths, about three 

 feet, separated from each other by about half an inch of asphalt. 

 These short rails are electrically insulated from each other, and 

 the current is directed into each of them in succession as the car 

 passes over them. This, as is well understood, is to prevent the 

 excessive leakage that would take place if a long length of rail 

 were in connection with a wet roadway, and also to prevent other 

 vehicles making a short circuit between the contact rail and the 

 return-current rail. The connection of the short rails with the 

 copper conductor is made by a magnet on the car acting on a 

 contact-maker under the rail, one end of this contact-maker being 

 joined to the conductor. On the under side of the car is a very 

 powerful electro-magnet about one and a half times the length of 

 a rail. At each end it has a pole-piece, consisting of a roller run- 

 ning on the rail, and two blocks just clearing the rail. This 

 magnet is energized by the main current, and consumes one hun- 

 dred and twenty to one hundred and fifty watts, although sixty 

 are said to be sufficient for the purpose, under favorable circum- 

 stances. The rail, which is five or six inches deep, stands on a 

 longitudinal earthenware sleeper; and the whole is solidly em- 

 bedded in a mass of asphalt, which extends below the sleeper. In 

 a groove in the sleeper runs the conductor, and in a second groove 

 is laid a strip of galvanized hoop iron. This strip is connected at 



one end to the conductor, and the other end is free. When the 

 magnet passes over it, the rail attracts the iron, which rises, and 

 makes contact with it. The current then flows from the con- 

 ductor through the strip to the rail, and thence by a bush to the 

 motor on the car. Neither the strip nor the rail has any special 

 contact surfaces. They are both galvanized, and there is no other 

 means provided to insure good connection. As soon as the mag- 

 net has passed, the rail ceases to be magnetic, the strip falls back, 

 and that particular rail is again insulated, its office being taken 

 by the one in front of it; and so on. The principal feature of 

 novelty lies in the use of a second, or so-called 'hidden rail," 

 placed alongside the contact rail underground, and, like it, em- 

 bedded in the asphalt. This is also in short lengths, but it is dis- 

 posed so as to break joint with the first rail, and thus reduce the 

 resistance of the magnetic circuit. It is stated that by the use of 

 this second rail a very much less powerful magnet is able to move 

 the contacts. The inventor seems to have aimed at cheapness of 

 construction ; and it is feared that difficulties will arise in practice 

 from the crudeness of some of his arrangements, although a 

 short experimental line in the yard of the West Metropolitao 

 Tramway Company, Chiswick High-Road, works very well. 



— Miss C. W. Bruce offers the sum of six thousand dollars dur- 

 ing the present year in aiding astronomical research. No restric- 

 tion will be made likely to limit the usefulness of this jiift. In 

 the hope of making it of the greatest benefit to science, the en- 

 tire sum will be divided, and in general the amount devoted to a 

 single object; will not exceed five hundred dollars. Precedence 

 will be given to institutions and individuals whose work is already 

 known through their publications, also to those cases which can- 

 not otherwise be provided for, or where additional sums can be 

 secured if a part of the cost is furnished. Applications are in- 

 vited from astronomers of all countries, and should be made to 

 Professor Edward C. Pickering, Harvard College Observatory^ 

 Cambridge. Mass., before Oct. 1, 1890, giving complete informa- 

 tion regarding the desired objects. Applications not acted on 

 favorably will be regarded as confidential. The unrestricted 

 character of this gift should insure many important results to 

 science, if judiciously expended. In that case it is hoped that 

 others will be encouraged to follow this example, and that event- 

 ually it may lead to securing the needed means for any astronomer 

 who could so use it as to make a real advance in astronomicat 

 science. 



— The increasing importation of foreign meat to England has 

 resulted in the invention of a number of refrigerating appliances,, 

 among them Hill's patent system of dry-air refrigerating appa- 

 ratus, which is on view at the working dairy at the Royal Military 

 Exhibition, Chelsea, Eng., and at the offices of the company,. 

 114 Cannon Street, London. The distinctive feature is that no 

 machinery is in use, the cold air being produced from the distilla- 

 tion of ammonia gas, a principle which is not by any means new. 

 The apparatus consists of steam-generator, ammonia boiler, sepa- 

 rator, and condenser for producing cold, and a refrigerator or cold 

 chamber. This chamber, as described in Engineering, is con- 

 structed in most cases of a double casing of wood, lined with 

 charcoal as a non-conductor; and the roof is formed by a tank 

 containing a bath of chloride of calcium liquor in sufficient quantity 

 to store up the cold as produced. In the case of the apparatus 

 exhibited on Cannon Street on Wednesday, June 25, the chamber 

 was seven feet by nine feet by seven feet high, and the ammonia 

 boiler two feet diameter by ten feet long. The solution of am- 

 monia in the boiler is heated by steam from any boiler, or from 

 a specially constructed slow -combustion stove, with a spiral coil 

 giving large heating surface. Alongside it is placed a water sep- 

 arator for drying the steam, which passes to a boiler three foiu-ths 

 filled with a solution of ammonia. To this the steam entering by 

 several pipes imparts heat, driving the ammonia into the form 

 of gas. Above the boiler is placed a separator for taking off 

 water carried forward in the distillation of the ammoniacai. 

 gas. The water thus separated passes by gravitation to the boiler. 

 Alongside it is a corresponding cylindrical vessel into which the 

 dried ammoniacai gas passes, and there it is condensed by its own 

 accumulation of pressure, and the latent heat carried off by the 



