ON DRAWING, WRITING, AND MEASURING. 97 



l>eing first washed with size, and then primed with an oil colour, which is usu- 

 ally white, but sometimes dark. Some painters have, however, preferred a 

 ground of distemper. The glare of the oil colours, or of tlie varnish, which 

 is added in order to give them brilliancy, is considered as an inconvenience 

 attending oil paintings; and some of the colours are too liable to fade or to 

 blacken by the effect of time. 



The encaustic paintings of the ancients were imperfect approximations to 

 the art of painting in oil. Wax or resins were employed for retaining the 

 colours in their places ; and they were api)lied by means of a moderate heat. 

 An effect nearly similar is produced by dissolving the resins in spirits of wine, 

 as is done in painting in varnish. A much greater degree of heat is required 

 for paintings in enamel: for this purpose the colours are mixed with a glass 

 of easy fusion, and, when finely powdered, they are usually ap])lied with oil of 

 turpentine, or sometimes oil of lavender, to a ground of metal or porcelain; ' 

 they are afterwards fixed and vitrified by exposure to the heat of a furnace. 



Mosaic work is performed by putting together small pieces of stone, or 

 baked clay, of various colours, so as to imitate the effects of painting: in tapes- 

 try, and in embroidery, the same is done by weaving, or working in, threads of 

 different kinds. 



The art of writing is of great antiquity, but it is probably in all countries, 

 and certainly in some, of a later date than that of drawing representations of 

 nature. The Mexicans, at the first arrival of the Spaniards in South America, 

 are said to have employed drawings as a mode of conveying intelligence; 

 some of them simply resembling the objects to which they related, others in- 

 tended as hieroglyphics ; that is, like the antient Egyptian characters, of a 

 nature intermediate between drawing and writing. The Chinese have always 

 used arbitrary marks to represent whole words, or the names of external ob- 

 jects, not resembling the objects to which they relate, nor composed of letters 

 appropriated to constituent parts of the sound, although they are said to be 

 combined froni a few hundred radical characters expressive of the most simple 

 ideas. The art of writing with alphabetical letters must have been suffici- 

 ently understood, in the age of Moses, to serve the purpose of the promulga- 

 tion of laws and of religion : it is generally supposed to have been invented 



VOL. I. o 



