76 



SCIENCE. 



[Vol. XIV. No. 339 



while oil-refuse from Baku is being used as household fuel by the 

 Russians, and, as soon as cheap suitable stoves are introduced, the 

 population will probably become more and more accustomed to 

 rely upon oil for fuel purposes. Every step in this direction is a 

 boon, because it tends to save more and more the timber in Cen- 

 tral Asia, and thereby contributes to a reforesting of a country 

 once densely covered with trees, and at that period famous through- 

 out Asia for its fertility. This fertility the Russian engineer is now 

 attempting to gradually restore. 



— The question of permeability of cements and mortars has 

 been treated of by the board of experts appointed to report on the 

 Washington Aqueduct Tunnel. In their report it is stated, that, 

 even if the brick lining of the tunnel were carefully made and 

 backed, still leakage could not be prevented, as bricks are them- 

 selves pervious under somewhat moderate heads. In some experi- 

 ments made by Mr. Francis last year, about 13.8 gallons of water 

 per square foot of surface passed through a thickness of nearly 16 

 inches cement in twenty-four hours, under a pressure of tj pounds 

 per square inch. Mr. Stauffer, another engineer, constructed a 

 bulkhead of brick-work in cement in the Dorchester Bay Tunnel, 

 which measures 10 feet by 10 f^t. Under a pressure of 72 pounds 

 per square inch, water percolated through at the rate of 96,000 

 gallons per day. Experience on the Boston main drainage work 

 showed that it was not practicable to build a brick bulkhead which 

 should be tight for pressures exceeding 64 pounds per square inch, 

 and at the Croton Reservoir water under 36 feet head was 

 found to percolate through 26 inches of brick-work and 4 feet of 

 concrete. In some experiments made by the board of experts 

 themselves, a good fair specimen brick was exposed to a pressure 

 of 80 pounds per square inch on one of its faces ; and, under these 

 conditions, 23.4 cubic inches of water passed through the brick in 

 the first hour, and 21.3 in the second hour. The mean of these 

 figures is equivalent to 1.4 gallons per square foot of surface per 

 hour. In the case of another brick under the same pressure, 46.8 

 cubic inches passed through in one hour. Blocks of cement mor- 

 tar allowed to set for twenty-four hours in air, and afterwards 

 hardened for five weeks in water, were also tested. Under 80 

 pounds pressure, water passed through these at the rate of 36.4 

 gallons of water per hour. The above figures have been reduced 

 to English gallons of 10 pounds of water. 



— The circular of the local committee for the meeting at To- 

 ronto, Ontario, Aug. 27 to Sept. 7, of the American Association for 

 the Advancement of Science, states that arrangements have been 

 made on the certificate plan for a very general reduction of rail- 

 way-fares over the principal railways embraced in the territory of 

 each of the different passenger agents' associations. Full fare for 

 limited or unlimited tickets, as the case may be, will be paid going 

 to Toronto, the purchaser receiving from the ticket-agent at the 

 starting-point, or at the one nearest thereto in the association, a 

 certificate giving the initials of the railways in the route to be 

 traversed, and the amount of fare paid. A certificate must be 

 taken covering the route in each passenger agent's association, if 

 more than one is traversed. Conductors of trains and ticket- 

 agents will be able to give full information as to the limits of each 

 association's territory. Upon the presentation of such certificate, 

 properly filled in and signed by the agent at the starting-point, and 

 indorsed by the local secretary at Toronto, a return ticket will be 

 sold, within thr^e days after the meeting, for one-third the regular 

 first-class fare. Return tickets will be sold at this price only over 

 the route traversed in going to Toronto. Persons must obtain 

 their blank certificates from the local secretary, Professor Loudon, 

 at Toronto. These certificates will be mailed, with full instruc- 

 tions for their use, upon application to the local secretary. A 

 separate certificate will be needed for each person coming to the 

 meeting. Members and others making application for certificates 

 will confer a favor upon the committee by enclosing an addressed 

 envelope for the reply. The railway companies will adhere to the 

 following rule : " No refund of fare will be made on any account 

 whatever because of failure of the parties to obtain certificates." 

 It will therefore be noticed that any person failing to obtain from 

 the agent selling the ticket to Toronto, such a certificate as has 

 been above described, will be obliged to pay full fare both ways. 



Those who desire to secure rooms in advance should communicate 

 either directly with the hotels or with William McCulloch, secretary of 

 the Young Men's Christian Association. The morning and afternoon 

 meetings of the association and of its sections will be held in the 

 University Buildings, Queen's Park, where will also be the offices 

 of the permanent and local secretaries during the meeting. Hotel 

 headquarters will be at " The Queen's," and the local committee's- 

 office in the vicinity at 42 York Street, where application may" be 

 made for information. In order to enable members to attend the 

 morning and afternoon sessions without being obliged to go to the 

 hotels in the interval, a luncheon will be served daily in the dining- 

 hall. University College. Through the courtesy of the post-office 

 authorities, there will be a branch post-office at the university dur- 

 ing the meeting. All Inail matter should be addressed " Care of 

 A.A.A.S." The Great North-Western Telegraph Company has- 

 liberally offered to transmit free the social messages of members 

 when approved by the secretary. No concessions could be ob- 

 tained over the United States lines. The Canadian Express 

 Company has generously offered to carry free packages containing 

 scientific articles intended for use at the meeting. Members will 

 receive whatever additional favors the local committee or the asso- 

 ciation may be able to secure or give, if they will send such pack- 

 ages in care of the local secretary. By the courtesy of the minister 

 of customs, all articles intended for use at the meeting will be ad- 

 mitted free ; subject, however, to inspection by the customs officers. 

 In case any difficulty arises at the frontier, members are recom- 

 mended to ship the articles by express in bond to the local secre- 

 tary. Full reports of the proceedings will be published in the 

 Toronto daily papers. Authors will oblige by sending, in advance, 

 abstracts of their papers (other than those sent to the permanent 

 secretary) to James Hedley, Monetary Times, Toronto, who will 

 withhold them from publication until the papers have been read in 

 the sections. The council will meet at the Queen's Hotel at noon- 

 on Tuesday, Aug. 27. The association will be called to order in 

 general session at 10 a.m., on Wednesday, Aug. 28, in the Uni- 

 versity Convocation Hall, by the president. Major J. W. Powell of 

 Washington, who will resign the chair to the president-elect. Pro- 

 fessor T. C. Mendenhall of Terre Haute, Ind. After the adjourn- 

 ment of the general session, the sections will organize in their re- 

 spective halls. In the afternoon the sections will meet and the 

 vice-presidents deliver their addresses. In the evening Major 

 Powell will deliver the presidential address in the Pavilion, Horti- 

 cultural Gardens. The meetings of the sections will be held on 

 the following days (except Saturday and Sunday) until Tuesday 

 night, when the concluding general session will take place. Sat- 

 urday will be devoted to excursions complimentary to the associa- 

 tion, including one to Niagara Falls and one to Muskoka. 



— Thomas G. Farrell writes from Portland, Ore., to the Ameri- 

 can Field, that, the varieties of native song-birds in this country 

 being rather limited, several German citizens some time since 

 conceived the idea of importing a number of German song- 

 birds. In a few days quite a respectable sum was raised for this 

 purpose, and forwarded to Germany. Not long since, the birds ar- 

 rived in charge of a competent keeper, and, after being placed on 

 exhibition for a few days, were all turned loose to multiply and 

 prosper. There were some three hundred birds in all, consisting 

 mainly of chaffinches, goldfinches, greenfinches, bullfinches, star- 

 lings, nightingales, skylarks, German robins, linnets, thrushes, 

 grossbeaks, and, last but not least, several specimens of the sing- 

 ing-quail. It is understood that many of them have been observed 

 nesting, and it is very likely that they will form a valuable addition. 



, to our feathered family. 



— At a recent meeting of the German Meteorological Society in 

 Berlin, according to Nature, Dr. Lang of Munich read a paper on 

 " The Velocity of Propagation of Thunder-Storms in South Ger- 

 many in the Ten Years 1879-88." This is, on an average, 38.4. 

 kilometres per hour ; but it has varied considerably from year to 

 year, increasing in the years to 1884, and thereafter decreasing. 

 To this corresponds a curious variation of Van Bebber's fourth 

 and fifth depression-paths, which lay in the north at the beginning 

 of the period, then moved south to South Germany till 1884, after 

 which they retired northwards. Hail frequency has varied in an 



