Scientific Intelligence. — Arts. 197 



lity of the limits of this error is represented by the fraction one- 

 half, since there is one to one, or one to two, to be laid that the 

 error which may have been committed will not exceed the limit 

 of two months and a fraction, and as much to lay that it will 

 surpass them in its limits. 



AETS. 



17. Extent of the Iron Trade of Great Britain. 



In the year 1740, the whole iron made in Great Britain was 17,000 tons, 



from 59 furnaces. 

 In 1788, it had increased to 68,000 tons, from 121 furnaces. 

 In 1796, it had increased to 125,000. 

 In 1806, it had increased to 250,000. 

 In 1820, it had increased to 400,000. 

 In 1827, it had increased to 690,000 tons, from 284 furnaces. 



The different counties in which it is made are as under in 

 1827: 



216,000 tons, from 95 furnaces. 



78,000 tons, from 31 furnaces. 

 272,000 tons, from 90 furnaces. 



24,000 tons, from 12 furnaces. 



43,000 tons, from 24 furnaces. 



20,500 tons, from 14 fiirnaces. 



36,500 tons, from 18 furnaces. 



690,000 tons. 284 furnaces. 



Staffordshire, 



Shropshire, 



South Wales, 



North Wales, 



Yorkshire, 



Derbyshire, 



Scotland, 



' About three-tenths of this quantity are of a quality suitable for 

 the foundry, which is all used in Great Britain and Ireland, with 

 the exception of a small quantity exported to France and Ame- 

 rica. The other seven-tenths are made into bars, rods, sheets, 

 &c. of which a large quantity is exported to all parts of the 

 world. — Repertory of Arts, October 1828, and Annals of Phil, 

 Jbr Nov. 1828. 



18. Russian Coinage of Platina, — A letter from Professor 

 Breithaupt to Dr Schweigger, an extract of which is g^ven 

 in a late number of the Jarhbuch der Chemicy Sfc. confirms 

 the statement some time since made by the newspapers, that 

 the Russian Government had resolved to coin a large sum in 

 Siberian platina. It appears that Count Denidoff, the proprie- 

 tor of the locality where the platina was discovered, has dis- 

 posed of to the government the quantity of that metal which 



