PAPER MAKING. 33? 



In using such cords, the moisture does not continue in the line of 

 contact between the paper and the cord, which prevents the sheet 

 from stretching in that particular place by its weight, and from the 

 folds which the moisture in the subsequent operations might occa. 

 sion. The Dutch also employ cords of considerable thickness, and 

 place fewer of them under the sheets ; by which means they dimi- 

 nish the points of contact, and give a freer and more equal circula- 

 tion to the air. 



The size for paper is made of the shreds and parings got from 

 tanners, curriers, and pnrchment.makers. All the putrefied parts 

 and the lime are carefully separated from them, and they are in- 

 closed in a kind of basket, and let down by a rope and pulley into 

 the cauldron. This is a late invention, and serves two valuable 

 purposes. It makes it easy to draw out the pieces of leather when 

 the HZC is extracted from them by boiling, or easy to return them 

 into the boiler if the operation is not complete. When the sub. 

 stance is sufficiently extracted, it is allowed to settle for some time ; 

 and it is twice filtered before it is put into the vessel into which 

 they dip the paper. 



Immediately before the operation, a certain quantity of alum is 

 added to the size. The work. man takes a handful of the sheets, 

 smoothed and rendered as supple as possible, in his left hand, dips 

 them into the vessel, and holds them separate with his right, that 

 they may equally imbibe the size. After holding them above the 

 Tessel for a space of time, he seizes on the other side with his right 

 hand, and again dips them into the vessel. When he has finished 

 ten or a dozen of these handfuls, they are submitted to the action of 

 the press. The superfluous size is carried back to the vessel by means 

 of a small pipe. The vessel in which the paper is sized is made of 

 copper, and furnished with a grate, to give the size when necessary 

 a due temperature : and a piece of thin board or felt is placed be. 

 tween every handful as they are laid on the table of the press. 



The Dutch are very careful in sizing their paper, to have every 

 sheet in the same handful of equal dryness ; because it is found that 

 the dry sheets imbibe the size more slowly than those which retain 

 some degree of moisture. They begin by selecting the padges in the 

 drying-house ; and after having made them supple, aud having de. 

 stroyed the adherence betweea the sheets, they separate them into 

 haudfuls in proportion to the dryness, each of them containing that 

 number which they can dip at one time. Besides this precaution, 



vot. vi. 



