1S2 WRITING. 



adopted by the celebrated Didot of Paris, and ultimately brought to 

 perfection by the late Earl Stanhope. It must be understood, that 

 stereotype plates are only adopted for standard works, and those likely to 

 have a large sale, because the outlay is considerable, although the con- 

 veniences are very great, inasmuch as a reprint can take place at any 

 time, and any required number, however small, can be taken off with 

 the greatest facility, and the expence of recomposition in thus saved. 

 "We shall describe briefly the casting of the plates. The pages of the 

 type are tied up separately, and the letters being rubbed over with an 

 oily composition to make the mould come away freely, Gypsum 

 (plaster of Paris) is then poured in a fluid state very carefully over them. 

 This quickly setting, the mould is removed, and if the impression is 

 perfect, the edges of the cast are dressed with a knife. The moulds are 

 then baked in an oven of a settled temperature, and made by such 

 means dry and hard. The mould is now placed in the casting-box 

 upon what is called a floating plate, with its face downwards ; the cover 

 of the casting box is then screwed down, suspended by a crane over the 

 pit which contains the molten metal, gradually lowered into it, and kept 

 steadily there by a lever and weight; the lid of the box being open at 

 the corners, the hot metal rushes in, and the nice interstices of the 

 mould are filled up. It remains here about ten minutes, and is then 

 swung into the cooling trough filled with water. The mould is then 

 beaten away by a wooden mallet from the plate now cast, the superfluous 

 metal broken off; the back of the plate is afterwards made of a sufficient 

 thickness by means of a lathe (the letters standing from its face of a 

 proper height), the stereotype is carefully examined, any excrescence picked 

 off, and the process is complete. The plates are a little longer (we mean 

 by the margin) than the pages of the moveable types, and if kept with 

 care will produce any number of impressions, equal to the ordinary type. 



WRITING. 



IN the early ages of the world a rock, a stone, or a metal plate was used 

 as the means of communication. " Come up to me into the mount and be 

 there, and I will give thee tables of stone, and commandments which I 

 have written." Exodus, Chapter xxiv. Again Job, chapter xix. "Oh! 

 that my words were now written. That they were graven with an iron 

 pen and lead in the rock for ever." The poems of Homer are said to 

 have been written on plates of lead, and many ancient documents are still 

 extant in India, written upon copper ; the tablet stone is frequently met 



