370 PHILOSOPHICAL TRANSACTIONS. [anNO 1788. 



which, when dug round, was found to measure 3 yards from n. to s., 24 yards 

 from E. to w., and about 4- of a yard in thickness ; the viceroy of the river 

 Plata sent me with orders to examine this discovery with accuracy ; and, in case 

 I found it a beneficial mine, that I should establish a colony there. I accord- 

 ingly set off, well escorted, in the beginning of Feb. 1783, from Rio Salado, 

 an ancient civilized hamlet of the Indians whom we call Vilelas, and pursued 

 my journey in the direction e. -f n. e. though on further examination I found 

 that I ought to have taken my direction e. ^ s. e. both corrected. 



The aspect of the country between the river and the mine, distant 70 leagues 

 from the settlement, is curious : it consists of an immense plain, alternately in- 

 termixed with thick woods and fertile fields, forming most pleasing landscapes. 

 The latitude of the mine I found, by observation, to be 27° 28' s. There is 

 not one fixed place of habitation throughout the whole country, owing to a 

 scarcity of running water. That which is drank by the honey-gatherers, who 

 reside there in small bodies the greatest part of the year, collecting honey in 

 the woods, is rain water, as I have alneady observed. These, and a few roving 

 tribes of barbarous Indians, who resemble the Tartars in their way of life, and 

 come hither, at a certain season of the year, from the borders of the river 

 Vermejo, in quest of a wild root, which they call Koruu, and which they con- 

 stantly chew, as a remedy against the pestilential air of their native country, and 

 also as a preservative against the bite of poisonous reptiles, are the only people 

 ever seen in those pleasant and extensive plains. 



I arrived the 15th of Feb. at the place called Otumpa, where the mass was 

 found almost buried in pure clay and ashes. The exterior appearance of it was 

 that of perfectly compact iron ; but on cutting ofF pieces of it, I found the in- 

 ternal part full of cavities, as if the whole had been formerly in a liquid state. 

 I was confirmed in this idea, by observing on the surface of it the impressions 

 as of human feet and hands of a large size, as well as of the feet of large birds, 

 which are common in this country. Though these impressions seem very per- 

 fect, yet I am persuaded that they are either a lusus naturae, or that impressions 

 of this nature were previously on the ground, and that the liquid mass of iron 

 falling on it received therti. It resembled nothing so much as a mass of dough, 

 which, having been stamped with impressions of hands and feet, and marked 

 with a finger, was afterwards converted into iron. 



I began to cut off part of it with chissels ; and in separating from the mass 

 25 or 30 pounds, I spoiled all the chissels I had, to the number of 70. I or- 

 dered my men to dig round it, and found the under surface covered with a coat 

 of scoriae from 4 to 6 inches thick ; undoubtedly occasioned by the moisture of 

 the earth, because the upper surface was clean. Having moved it half round, 

 by means of handspikes, I ordered the ground under its bed to be dug to a con- 



