184 Mr. Cowper on the 



reotype founding-, — the process of which is as follows, — a brass 

 frame is placed round the form of types ; plaster of Paris, mixed 

 with water to the consistence of cream, is then poured on the type, 

 the superfluous plaster being scraped off. When the plaster is 

 hai-d, the mould is lifted off by means of the brass frame, and from 

 which it is readily detached — it is now baked in an oven, and when 

 well dried and quite hot, it is placed in an iron box or casting-pot, 

 which has also been heated in the oven ; it is now plunged into a 

 large pot of melted type-metal, and kept about ten minutes under 

 the surface, in order that the weight of the metal may force it into 

 all the finest parts of the letters, — the whole is then cooled, the 

 mould broken and washed off, and the back of the plate turned in 

 a lathe. This manufacture has been carried to a considerable ex- 

 tent ; Mr. Clowes, the proprietor of one of the largest and best- 

 conducted printing-offices in London, has on his premises between 

 700 and 800 tons of stel-eotype plates, belonging to various book- 

 sellers, — the value may be estimated at .£200,000. 



In connection with the Stanhope press, may be briefly noticed a 

 Jittle improvement for the particular purpose of printing music, 

 after a new process, and for which I have obtained a patent. — In 

 this new process the lines are formed of thin slips of copper driven 

 into small blocks of wood, and the notes are formed of copper 

 ^driven into a separate block. Two note blocks and two corre- 

 sponding sets of lines are placed on the table of the Stanhope press ; 

 to the ordinary tympan of the press is attached another tympan, 

 which revolves in the direction of its plane on a pin in the ordinary 

 tympan. Two sheets of paper are pla9ed under two friskets, 

 hinged to the revolving tympan ; an impression being now taken, 

 one sheet will receive the notes, and the other the lines. The re- 

 volving tympan is then turned half round, when the sheets will 

 have changed places, another impression is taken, when both 

 sheets will be perfected. — This plan is now in operation at the 

 printing-office of Mr. Clowes, to whom I have assigned the 

 exclusive use of the patent. 



It was in the year 1790, that Mr. W. Nicholson took out a pa- 

 tent for certain improvements in printing, and on reading his spe- 

 cification, every one must be struck with the extent of his ideas on 

 this subject ; to him belongs, beyond doubt, the honour of the 

 first suggestion of printing by means of cylinders : the following 

 are his own words, divested of legal redundancies — 



" In the first place, I not only avail myself of the usual methods 

 of making type, but I do likewise make and arrange them in a 

 new way, viz. by rendering the tail oif the letter gradually smaller, 



