260 HEROES OF SCIENCE. 



Years rolled on, and Smith's wanderings over 

 England and their results were laid down by him 

 on a map, which was to be published. With regard 

 to this map of the strata, it may be said that it was 

 very trying work for the publisher as well as the 

 author. The basis of the map, as already explained, 

 was in many respects peculiar ; the colouring of it 

 was more so. Instead of ih^flat colouring ending 

 in narrow defined edges usually employed for maps, 

 Mr. Smith introduced a peculiar style of full tints 

 for the edges of the strata, softened into the paler 

 tint employed for the remainder of the area which 

 they occupied on the surface. This new style of 

 colouring gave a picturesque effect to the map, but 

 required more than usual skill and patience to be 

 correctly executed, and occasioned great trouble in 

 examining the copies. The colouring of the map 

 was thus rendered more expensive than had been 

 anticipated, and notwithstanding the labour was well 

 paid for, it was not always at first properly per- 

 formed. 



At length the difficulties inseparable from such 

 a task were so far overcome, and this enormous 

 labour was so far completed, that a coloured map 

 of the strata of England and Wales was submitted 

 to the consideration of the Society of Arts, sup- 

 ported by various testimonials of its general ac- 

 curacy and value, in April and May, 1815. The 

 result was the award of the premium of £^0, which 

 had been in vain offered for very many years for a 

 work of this description — a reward which Mr, 



