50 ANNUAL OP SCIENTIFIC DISCOVERY. 



in its green state, than to prepare it after the time necessary for its complete 

 dessication had sensibly altered it." 



Tredgold, in his able and lucid manner, accounts for the effects upon tho 

 durability of timber, produced by these processes, which have thus been 

 condemned. He says that "it is well known to chemists, that slow drying 

 will render many bodies less easy to dissolve, while rapid drying, on the 

 contrary, renders the same bodies more soluble; besides, all wood in drying 

 loses a portion of its carbon, and the more in proportion as the temperature 

 is higher. There is in wood that has been properly seasoned a toughness and 

 elasticity which is not found in rapidly dried wood; and this is an evident 

 proof that firm cohesion does not take place when moisture is dissipated at 

 a high heat." 



The employment of Bethell's and Burnett's process upon American rail- 

 ways, are open to serious objections, both on account of the expense of 

 apparatus, and difficulty of locating it along the route under construction. 

 AVhat is wanted is some process which shall be cheap, simple, and efficacious. 

 Boucherie's system of introducing the solutions longitudinally, through 

 pores or tubes of the timber, by the pressure of a column of any convenient 

 height, is a step in the right direction to meet these necessities. In a recent 

 improved process, brought out by Mr. John Reed, Jr., of Glasgow, the fol- 

 lowing course is pursued : " After the tree has been felled, a saw-cut is made 

 across the centre, through about nine-tenths of the section of the tree, which 

 is slightly raised at the centre by a lever or wedge, so as to open the saw-cut 

 a little; a piece of string or cord is placed around the edge of the saw-cut, 

 and lowering the tree again, the cut closes on the string, which thus forms a 

 water-tight joint; an auger-hole is then bored obliquely into the saw-cut, 

 from the outside, into which is driven a hollow wooden plug; a flexible tube 

 is fitted on the plug, the end of which is made slightly conical, so that the 

 tube may be pushed tight upon it; the fluid flows from a cistern, at an 

 elevation of from 30 to 40 feet." 



Mr. Reid further adds, that the timber is most successfully operated upon 

 within ten days after being felled, in which event, the process with a log 9 

 feet long will occupy twenty-four hours. If the timber is felled three months, 

 three days are required; if four months, four days. 



To expedite the longitudinal transmission of solutions, an ingenious appar 

 ratus has been conti'ived by John L. Pott, Esq., of Pottsville, some idea of 

 which can be formed by the following description : 



It consists of a force-pump, to the cast-iron frame of which is bolted a 

 strong cylinder, also of cast iron, 9 feet long, the inside diameter being 12 

 inches. Into the further end of the cylinder a hollow cast-iron collar is 

 accurately fitted, but can be withdrawn and replaced at pleasure, the joint 

 being water-tight. From the sectional end of the collar which is foremost 

 in the cylinder, there extends a rectangular punch, sharpened and edged with 

 steel, the area of which being less than the cross section of the railroad sills 

 in use. This is driven by beetles into the end of the sill placed in the cylin- 

 der, and then firmly secured by strong bolts connected with the apparatus. 

 This plan of cylinder-head makes a water-tight joint, and at the same time 

 allows the sap to escape, and secures a greater pressure at the end of the sill 

 which lies against the pump. The power is applied by hand, with a crank. 

 The writer, experimenting with this apparatus, found that in certain classes 

 of timber which were freshly cut, the sap would be driven out with great 

 force, rapidly followed by the solutions. This was noticed especially with 



