1 58 HEROES OF INVENTION AND DISCO VER K 



which would undoubtedly give an impression all black; and 

 that by scraping away proper parts, the smooth superficies 

 would leave the rest of the paper white. Communicating 

 his idea to Walleraut Vaillant, a reputable painter then in the 

 neighbourhood of Brussels, they made several experiments, 

 and at last invented a steel roller with projecting points or 

 teeth like a file, which effectually produced the black ground, 

 and which being scraped away or diminished at pleasure left 

 the gradations of light. 



Such was the invention of mezzotinto, according to Lord 

 Orford, Mr. Evelyn, and Mr. Vertue, though in all fairness we 

 must state that it has been disputed by some, and the credit 

 assigned to a German, Von Tregen, whose early works bear 

 the date of 1642. 



The earliest of Rupert's engravings in mezzotinto that is 

 now extant is dated 1658. It is a half-length figure from 

 Spagnoletto : the subject, an executioner holding a sword in 

 one hand, and in the other a head, which is probably intended 

 for that of John the Baptist. 



Prince Rupert died at his house in Sprmg Gardens, 29th 

 November, 1682, and was interred in Henry VIII. 's chapel, 

 regretted as one whose aim in all his actions and all his 

 accomplishments was the public good. 



STTv SAMUF;L IsrORLAND. 



As a machinist. Sir Samuel Morland, who was born aboiu 

 1625, deserves more respect than has hitherto been paid to 

 him. He invented the speaking-trumpet, the fire-engine, a 

 capstan to heave up anchors, and two arithmetical machines, 

 of which he published a description under the title of " The 

 Description and Use of Two Arithmetical Instruments; toiiether 



