r6^4 PHILOSOPHICAL TRANSACTIONS. [anNO l/GS. 



mine, which he doubts not would abundantly furnish matter for cinder. If they 

 had used only the first, and that properly chosen, it might very probably have 

 been of some service, without doing any material injury to the metal ; but if the 

 bog mine is used, though the surface might be apparently more, yet in all like- 

 lihood the injury would be infinitely great; and he was inclined to believe that 

 something of this kind occasioned the difference observed between the 2 bars 

 above mentioned, viz. that the one might have been reduced by the help of more 

 pure materials, and the other by the assistance of their bog mine, whose consti- 

 tuent parts abounding with many impurities, some of which, by mixing with the 

 metal, may have occasioned the defects above complained of, and which required 

 so severe an operation both of the fire and hammer to separate from it. He was 

 therefore of opinion, that as the prosecution of this useful discovery deserved the 

 greatest encouragement, if the Society of Arts and Manufactures should take it 

 under their patronage, the premium they might think proper to propose should 

 rather be given to the person who should produce the purest metal, than to him 

 who should produce the greatest quantity ; for otherwise he was afraid they 

 would be deprived of what he should esteem the most valuable part of this disco- 

 very, he meant the obtaining a more pure, and better kind of iron, than any 

 they had hitherto been possessed of. 



XIF. On the State of the Cold at Berlin last Winter, dated Feb. 12, 1763. By 

 Simon Peter Pallas of that place, M.D. p. &1. 



We have had great frosts here, as indeed all over Germany. Dec. 27, a little 

 after seven o'clock in the morning, the cold was excessive, the mercury in the 

 thermometer of Fahrenheit stood at 4 degrees under O, which is 15 degrees under 

 of Reaumur's scale, than which the cold in 1740 was but very little more in- 

 tense. Mr. Euler, junior, observed the same day the thermometer at the same 

 degree ; about 8 and at Q o'clock of that day, the mercury in the barometer 

 stood at the height of 30'' \'", the like of which never had been observed at 

 Berlin before. 



XF^. Of a Remarkable Darkness at Detroit, in America. By the Rev. James 



Stirling, p. 63. 



Detroit, 25th Oct. 1762. 



Sir, 



Tuesday last, Oct. IQ, 1762, we had almost total darkness most part of the day. 

 The darkness continued till 9 o'clock, when it cleared up a little. We then for 

 the space of about a quarter of an hour saw the body of the sun, which appeared as 

 red as blood, and more than 3 times as large as usual. The air all this time, 

 which was very dense, was of a dirty yellowish green colour. We were obliged 



