72 ANNUAL OF SCIENTIFIC DISCOVERY. 



and the lirtin<T:-pit is thou ready for the rccci^tion of another vessel. 

 At the Victoria Docks there are thirty-two i)resses, Avith ten-inch 

 rams, havinjx a stroke of twenty-live feet. This, with a water 

 pressure of two tons per circular inch, <^ives a total liftiufj,- power 

 of 6,400 tons, less the Weight of crosshead.s, rams, etc., amounting 

 to six hundred and twent}' tons. — Popular Science lieview, April, 

 18GG. 



CORK SPRINGS. 



The use of cork instead of Tndia-ruhher as a support for freight 

 cars and similar heavy vehicles, would not, a priori, seem very 

 l)romising, from ordinary impressions of its properties. The cork 

 used for such springs is of the commonest (U'scrii)tion, harsh, hard, 

 and full ol fissures ; it is cut into disks of aljout eight inciies diam- 

 eter, each pierced witli a central hole. Previous, liowever, to cut- 

 ting, it is s(jaked in a mixture of molasses and water, which gives 

 it some softness, and renders it permanently moist. A numl)er of 

 these cork disks are placed in a cylindrical cast-iron box, a flat 

 iron lid or disk is i)laced over them, and Ijy liydraulic; pressure is 

 forced down so as to reduce the thickness to one-half. A bolt is 

 then run through box, corks, and cover, at the centre, and a nut 

 being scrcAved on this holds all in jjlace, when the press is 

 relieved, and the box of compressed cork, disks, or cork spring, is 

 ready for use. One of these springs, placed in a testing machine, 

 under a weight of 20,000 pounds, showed an elasticity suggestive 

 of comiircssed air in a cond(>nsing pump. One would expect, from 

 the appearance of the material, that, under heavy pressure, it 

 would be pulverized or s\)\\i into shreds, especially if this pressure 

 was assisted bj' violent shocks; but, in fact, no such action takes 

 place. A pressun^ which destroj^s ludia-rubljer, causing it to split 

 up and lose its elasticity, leaves the cork unimpaired; and, with 

 the machinery in use, it has even been impossible, with any press- 

 ui'e attainable, to injure the cork, even when areas of but one 

 inch were acted upon. — Journal of Franklin Institute, May, 18G6. 



ON THE PRESERVATION OF WOOD, IN DAMP AND WET PLACES. 



In 184G, 80,000 sleepers of the most perishable woods, impreg- 

 nated, by Boucherie's process, Avith sulphate of cojjper, Avere laid 

 down on French railways: after nine years exposure, they were 

 found as perfect as Avhen laid. We Avould suggest Avashing out 

 the sap Avith Avater, Avhich Avould not coagulate its albumen : the 

 solution Avould appropriately folloAA'. Both of the last named 

 processes are comparatively cheap ; it costs less than creosotin^, 

 by one shilling per sleeper. The unpleasant odor of creosote is 

 o-reatlv against its use for lumljer for dwellings ; pyrolignite of 

 iron isofi'ensive, and also highly inflammable ; the aiTinity of the 

 chlorides for Avater keeps the structure into Avliich they are intro- 

 duced wet, and they also corrode the iron-Avork. Sulphate of 

 copper is free from these objections, and is cheaper than the 

 chlorides, and seems preferable for protecting wooden structures 



