185 



The result of these experiments was as follows : 

 The wootz of the 1st cake reduced 0'139 its own weight of lead. 

 That of the 2nd 0-125 



3rd 0-120 



4th 0-156 



5th 0-102 



Steel containing -^ its weight of carbon 0*094 its own weight of lead. 

 White cast iron 0'228 



From these experiments, the author says, it appears, that wootz 

 contains a greater proportion of carbonaceous matter than the com- 

 mon sorts of cast steel, and that some particular cakes approach very 

 near to the nature of cast iron. This, added to the imperfect re- 

 duction, seems to him quite sufficient to account for its refractory 

 nature, and for the want of homogeneity in its texture. 



Notwithstanding the above imperfections, Mr. Mushet thinks wootz 

 possesses the radical principles of good steel, and that it is impossible 

 not to have a very high opinion of the excellence of the ore from 

 which it is produced ; the possession of which, for the fabrication of 

 steel and bar iron, would be an object of the highest importance. It 

 is, he -says, a subject of regret that such a source of wealth cannot 

 be annexed to the dominions of this country ; as in that case the East 

 India Company might supply their settlements with an article su- 

 perior in quality, and inferior in price, to any they send from this 

 country. 



Abstract of Observations on a diurnal Variation of the Barometer be- 

 tween the Tropics. By ,1. Horsburgh, Esq. In a Letter to Henry 

 Cavendish, Esq. F.R.S. Read March 14, 1805. \_Phil. Trans. 

 1805,^.177.] 



It appears from Mr. Horsburgh's journal, that in steady weather, 

 within the tropics, a regular elevation and depression of the baro- 

 meter takes place twice in every twenty-four hours, the greatest de- 

 pression being about four o'clock morning and evening, and the 

 greatest elevation being from eight in the morning till noon, and from 

 nine or ten in the evening till midnight. 



In a letter which accompanies the journal, dated Bombay, April 

 20th, 1804, Mr. Horsburgh says he has observed, since his arrival in 

 India, that the atmosphere appears to affect the barometer differently 

 at sea from what it does on shore. As a proof of this, Mr. Hors- 

 burgh gives a series of observations, made on two barometers, one 

 by Troughton, the other by Ramsden, of wlu'ch the following is an 

 abstract. 



From the time of leaving the Land's End, on April 19th, 1802, the 

 mercury was fluctuating and irregular, till April 29th, lat. 26 N., 

 long. 20 W., when it constantly performed two elevations and two 

 depressions every twenty-four hours. These Mr. Horsburgh calls 

 - equatropical motions. From lat. 26 to 10 the difference in the 

 high and low stations of the mercury was not so great as it was from 



