BUREAU OF AMERICAN ETHNOLOGY 



BULLETIN 52 PLATE 47 



Here are shown the exposed walls of the Pampean terrane and alluvium, the dram leadiiij; to the 

 sump, or well, and the pumping machinery close to the side walls of the gate. 



Here are shown the walls of the Tampean formation and allu^num still exposed after the concrete 

 noor nad been laid, with the sump and pumping machinery as in the view above. 



EXCAVATION FOR DRY DOCK 



(From original photographs in office of C. H. Wallcer & Co., Buenos Aires.) 



