Account of the Trona Lake in Africa. 387 



by different persons, at from 70 to 90 tons. On the first day, 

 when the rock was first swung in the air, in the presence of 

 about two thousand persons, much anxiety was felt by those 

 who were present, as to the success of the undertaking ; the 

 ropes were much stretched ; the pulleys, the sheers, and the 

 capstans, all screeched and groaned ; and the noise of the ma- 

 chinery was audible at some distance. Many were very ap- 

 prehensive lest so vast a weight might snap all the ropes, and 

 tumble over the precipice, bearing the sheers and scaffolding 

 away with it ; however, the whole has gone off with great suc- 

 cess. The materials (which were all furnished gratis, from 

 the dock-yard at Plymouth) were excellent, and ingeniously 

 managed ; and though a rope or two broke, and a link of one 

 of the chains tore away a small piece of an angle of the rock, 

 which was thrown with much velocity into the sea, yet the 

 rock was safely supported by its complicated tackling, and 

 stands, once more, in precisely its former position ! Lieutenant 

 Goldsmith, who threw it down, was the engineer in replacing 

 it; and, in the opinion of many of the gentlemen of this town 

 and neighbourhood, he has, by his skill and personal la- 

 bour and attention, not only wiped away the disgrace to which 

 he was exposed by throwing it down, but also acquired so 

 much merit, that they are about to invite him to a public din- 

 ner at Pearce's Hotel. This seems to be going a little too 

 far ; since whatever credit he may have derived by replacing 

 the rock, seems to be fully counterbalanced by the discredit 

 of its wanton demolition. It is understood that the expenses 

 of this work are defrayed by subscription. Fifty pounds 

 have been given by the London Geological Society." — Mom. 

 Chon. 



ACCOUNT OF THE TRONA LAKE IN AFRICA. 



The following account of this remarkable soda-lake is given 

 by Dr. Oudney, in a letter to Professor Jameson. 



" The Trona Lake is situated in the midst of amazingly 

 high sand-hills, that run for several hundred miles to the west- 

 ward, and lie between Wadies Shiati and Ghrurbi. It is in 

 a small valley which runs nearly ESE. and WNW. The 

 north and south sides are bounded by hills of sand about 400 

 feet high. The bottom is a fine sand, on which are found 

 the Agoul (apparently a species of Ulex), and a downy grass. 

 Near where we entered the valley, there is a cluster of date- 

 palms, and a small lake, from which impure trona is obtained. 

 On the western side is the trona lake, surrounded by date- trees, 

 and its banks and marshy borders covered, on almost all sides, 

 by the grass I have mentioned, and a tall juncus. It is about 

 half a mile long, and nearly 200 yards wide, of very inconsi- 

 3 C 2 derable 



