viATlO DISPATCH. 



S, ANIMAL. 





whii :. . ' h.\ 1'i-rl" a common 



: 1 terminating: at the 



periphery, in tangents, almost parallel to each 



me of iv\oltitiun. i 



disks an- -till'died ami connected h\ radial ribs, 

 ami tin- shaft is fixed in them by ril>-leathcr-. 

 Circiil.ir nioiitiis at the centre 01 tin- disk c<r- 

 :d to ."imiliar months terminating the 

 air-trunks, with which they make tight joint 



I'.v mi-ait', of ordinary onp-leathera. The \>r\>- 



..f the curve which determines the shape 

 of the di>k. is, that a circnnircivntial section at 

 t'rom the axis shall have the 

 >ame area, which also equals that of the in- 

 draught openings just described. This ivniark- 



ejector" appears capable of giving a 

 higher duty tlian any fan previously used, and 

 the actual pressures obtained, as will be seen 



fn.m the following table, are Htrictly propor- 

 tionate to the square roots of i 



By the use of this ejector, and of ippropriate 

 valves in the connecting pipes, the cars are 



Ki-. 1. 



blown tbroogh the tunnel from the Euston 

 Station, or sucked Lack from the further ter- 

 minus. In the first case, the necessary supply 

 of air is obtained from out of doors, by means 

 of passages under the floor, and in the latter 

 itdraught is discharged by the same 

 means. 



The arrangement for allowing the car to 

 come out of the tunnel at either terminus is 

 shown in Fip. 4, which represents the termina- 

 tion of the tube with its various appliances. 

 Al'ove, at the ri^ht, is seen a spring-valve, 

 which may he so adjusted that the resistance 

 otlered to the escape of air from in front of the 

 oar, when near the terminus, may he such as 

 to bring it to rest ut a convenient point outside. 

 Vertically under this is seen a wheel at the 

 tiid of a long lever, upon which presses the 

 ncing car. This lever, thus depressed, 

 free at its other end the detent of the 

 door, which closes the tube or tunnel, and a 

 counter-weight then quickly raises this last a 

 moment before the car reaches it. 



The velocity at which the cars or trains are 

 run in this tunnel is about 1G miles an hour, 

 the short curves before mentioned necosituting 

 a reduction of speed. This velocity is obtained 

 by the use of a 22-foot ejector, making 100 to 

 110 turns per minute, which develops a pres- 



-* ^ to 4 inches on a water-gauge. Mo- 



VOL. vii. 40 



tion is given to the ejector by means of a small 

 steam-engine of 15" diameter and 16" stroke, 

 set upon an inclined framing, and having its 

 crank keyed directly to the shaft of the ejector. 

 About 15 trains, each way, are now the daily 

 work done by this apparatus, which is but a 

 small percentage of it* capacity. 

 A The general arrangement of parts and ground 

 plan of the Euston terminus are shown in Fig. 

 2 : the right is the hoiler next to it, the engine 

 attached directly to the ejector, from which 

 two tubes lead to the tunnel, a long one for 

 suction, and a short, direct passage, for blow- 

 in:/. Opposite to the end of the tunnel, on the 

 farther side of the room, is a short closed pas- 

 j-aire, which acts as an air-buffer to the cars, 

 should the valve arrangement before described 

 fail to bring them to rest at the desired point, 

 namely, on the track between these twc. 



POISONS, ANIMAL. In some experiments 

 on th'- f the cobra di capella, which 



B 15. llalford, M. D., Professor of Anatomy 

 in the University of Melbourne, has been lately 

 vd in, he has discovered that when a per- 

 son is mortally bitten by the cobra, molecules 

 of living "germinal" matter are thrown into 

 the blood and speedily grow into cells. These 

 cells multiply so rapidly that in a few hours 

 millions upon millions are produced at the ex- 

 pjuseof the oxygen absorbed into the blood 



