May 2nd, 1887.] 



SCIENTIFIC NEWS. 



51 



tubing so heated sends out almost invisible filaments. 

 Canada balsam is the perfection of a material for producing 

 such sticky threads. When a candle is held near a cup 

 throwing out such electrified filaments they shoot into the 

 flame, and sometimes cover the candle; sometimes they 

 will stop as they approach the flame, then turn back, and go 

 into the cup from which they started, in consequence of 

 discharging the electricity into the flame. In a few minutes 

 miles of these sticky threads can be made, and as they 

 break into beads the method affords a ready means of 

 powdering such of these substances as are not easily pul- 

 verised in any ordinary way. 



The City and Southwark Subway. — There could hardly 

 be a better illustration of the progress of engineering 

 science during the last fifty years or so than the fact that 

 within a few months a tunnel beneath the Thames, close to 

 London Bridge, has been begun and finished with compara- 

 tively very few people being a bit the wiser. When 

 Brunei at last joined the two banks of the river by boring 

 under its bed, it was considered that another wonder had 

 been added to the world's stock, but now such a feat is a 

 matter of course. The tunnel referred to has been made 

 by the City and Southwark Subway Company. It is 

 designed to aft'ord an easy and rapid means of communi- 

 cation between the City and the Surrey side 01 the water. 

 There is to be a terminus at the Monument, and another at 

 Stockwell. The tunnel, or rather tunnels, for there is to 

 be a separate one for up and down lines, are not built for 

 either pedestrian or railway traffic as now generally under- 

 stood, but will be worked by a wire-rope system, much as 

 the old Blackwall Railway was in days that are fast getting 

 long since past. 



The great feature in the scheme, and the one on which 

 its promise of commercial success is based, is that no com- 

 pensation is to be paid for the use of land, damages to 

 business, etc., excepting in one trifling instance. The tun- 

 nels are to follow the lines of the public street, and where 

 the street is too narrow to allow them to be placed side by 

 side, they will be arranged one over the other. These 

 tunnels are carried at a sufficient depth to go under every- 

 thing — foundations of buildings, gas and water pipes, 

 and all other vested interests. Each tunnel is 10 feet in 

 diameter, and is composed of iron rings bolted together. 

 On account of the great depth at which the lines run, the 

 labour of getting up and down by ordinary stairs would be 

 excessive, so communication with the surface will be made 

 by hydraulic lifts. The practicability of this system has 

 been shown by the experience gained with the Mersey 

 Tunnel lift, where 100 passengers are carried at once 

 to heights of 76 teet and 87 feet. On the whole, the new 

 scheme seems to promise well, and if successful will no 

 doubt lead to other lines on the same plan being started. 

 It is certain that London is sadly in want of more facilities 

 for locomotion, and has used up all its surface area. 



GENERAL NOTES. 



Asbestos. -It is stated that an important and extensive 

 discovery of asbestos has been made in the Umsinga divi- 

 sion. South Africa. 



The Birmingham Cable Tramway, the construction of 

 which has been in contemplation for some months, has been 

 begun. The whole line will, it is hoped, be ready for use 

 in four months. 



Carbons. — -At a trial in Cleveland, U.S., for infringement 

 of patent, a witness testified that of 150,000 carbons burned 

 daily in the United States, 100,000 are manufactured in 

 Cleveland, where there are 20 furnaces. 



Gaslit Omnibuses. — The three-horse omnibuses of the 

 Metropolitan Railway travelling between Portland Road 

 Station and Charing Cross are now lighted with gas. They 

 each carry a store to last three or four evenings. 



Chemistry in Agriculture. — According to M. Adouard 

 it is wrong to mix nitrates with superphosphates in order 

 to spread them on the soil, as these salts react on one 

 another and some of the nitrogen is lost. — La Nature. 



Quicksilver in Russia. — Quicksilver is now being worked 

 near Nikitofka station on the Koursk-Kharkoff-Azoft" Rail- 

 way. A pit 280 feet deep is being sunk provided with the 

 necessary machinery. The ores arc expected to yield i per 

 cent, of metal. 



An Exhibition for Brussels. ^ — An application has been 

 made by the Belgian Government for a credit of ^72,000 

 to assist the establishment of a museum of industrial and 

 monumental art, and to found an industrial exhibition at 

 Brussels in 1888. 



Pollution of the Thames. — The Thames Conservators 

 have framed a bye-law to prevent the pollution of the upper 

 river by house boats and steam launches, and these vessels 

 will be required to make the necessary alterations and arrange- 

 ments to enable them to comply with the bye-law. 



Cork Bricks. — For some time past experiments have 

 been made in Germany with a composition of cork, sand, 

 and lime moulded into bricks for the construction of light 

 partition walls. This, it is said, excludes sound better than 

 brickwork, and is also light and a good non-conductor of heat. 



Resistant Filter-Paper. — A French chemist finds that 

 filter-paper, if dipped for a moment in nitric acid of the 

 density of i'42, and immediately washed in plenty of water, 

 becomes much stronger than before, and may be used for 

 filtering under pressure without the use of a protecting cone 

 for the tip. 



Iron from China Stone.— 77;« Engineer states that at 

 Par, Cornwall, a process, described as the " extraction of 

 iron from China stone by means of electricity," has been for 

 some time under experiment by the St. Austel Mining Com- 

 pany, and plant is now being laid down for the permanent 

 application of the process upon a commercial scale. 



A Method of Cracking Glass is given by E. Beckmann. 

 A scratch is made with a file ; at both sides of this, pads of 

 wetted filter paper are wrapped round the object, leaving a 

 space of a few millimetres between them. The flame of a 

 Bunsen or gas blowpipe is applied to this space, when the 

 crack will be carried round from the scratch mid-way 

 between the two pads. 



The Italian Navy. — The Italian Government are 

 having built and engined, in various parts of Italy, a number 

 of first-class torpedo boats similar to those purchased at 

 Elbing in Germany. The engineering works at Genoa are 

 consequently very busy, as they have in hand, besides, the 

 three ironclads, Sicilia, Re Uinberlo, and Sardinia, all of 

 which are to have engines of 20,000 horse-power. 



