246 LECTURE XX. 



In the midst of an age of darkness, an insulated individual arrests our at- 

 tention by merits of no ordinary kind. Roger Bacon was burn at Ilchester, 

 in the year 1214; it is well known that his experiments had led him to a 

 discovery of the properties of gunpowder, although he humanely concealed 

 the nature of its composition from the public, and described it only in au 

 enigma: the extent of his optical knowledge has been variously estimated^ 

 but it was unquestionably much greater than that of the ancient philosophers. 

 He appears, however, to have had some companions in his mechanical pur- 

 suits; he declares that he had seen chariots which could move with incredible 

 rapidity, without the helpof animals ; he describes a diving bell; and he says 

 that he had been informed, on good authority, that machines had been made, 

 by tlie assistance of which men might fly through the air, Cimabue, who 

 first began to revive the long neglected art of painting, was cotemporary with 

 Bacon. The use of oil in painting is commonly supposed to have been in- 

 troduced by Van Eyck, but there are traces, in the records of this country, of 

 its employment as early as the year 1235. 



The clepsydrae, or water timekeepers of the ancients appear to have been 

 gradually transformed, in the middle ages, into the clocks of the Saracens 

 and of the Arabians; and these were introduced into Europe in the thirteenth 

 century. About the year 1290, turret clocks were erected at Westminster and 

 at Canterbury. The first clock, of which we know the construction, is that 

 which was made by Wallingford in 1326, and which was regulated by a fly ; 

 and the second that of Defondeur, or Fusorius, with a simple balance, made 

 about 1400. But it appears that some portable watches had been constructed 

 in the beginning of the fourteenth century; and about the year 1460, several 

 clock makers are said to have come to England from Flanders. 



The art of engraving on metal, and of printing with the rolling press, is sup- 

 posed to have been invented in the year 1423. Some attribute the art of 

 printing with types, to Laurentius Coster of Haerleni, who, as they say, in 

 1430, employed for the purpose separate blocks of wood, tied together with 

 thread. Gensfleich, one of his workmen, went to Mentz, and was there as- 

 sisted by Gutenberg, who invented types of metal. But the best authors ap- 

 pear to disbelieve this story ; and Gutenberg, in partnership with Fust antl 



