G76 Transactions of the American Institute. 



fallen to their lodges. Some of these canals were three hundred, 

 four hundred, and even five hundred feet long. They were gene- 

 rally three feet wide, with an average depth of three feet. lu 

 order to maintain a continuous depth of water, they made dams at 

 certain disbances, and followed the Chinese plan — to whom the lock 

 was unknown — of drawing their cargo from one level to another. 

 Mr. Morgan has settled a long disputed point. From a comparison 

 of more than one hundred skulls of American beavers with four or 

 five of European origin, he is enabled to state that both classes 

 belong to the same siDecies. 



ORNAMENTAL IRON CASTINGS. 



The Paris Exposition contains samples of small ornamental work 

 of iron, known as "'Berlin castings," made at the iron works of 

 Count Stolberg, at Ilsenburg and Harz, in Brmiswick, which have 

 all the delicacy and beauty of outline of the best brass and bronze 

 castings. The models of iron doors, tables, church decorations, 

 <fec., are classic specimens of modern and mediaeval art, having the 

 sharp, minute impressions, and the fine finish of those produced by 

 the electrotype process. It has been generally believed that this 

 kind of work was made by mixing with the iron some metalloid, 

 Avhich has the effect of giving to the metal more fluidity and density, 

 but this is not the fact. The specimens are made of ii"on alone, and 

 are the result of the laborious researches and experiments of M. 

 Schott, the manager of these works. His attention was first 

 directed to the importance of procuring the finest quality of mold- 

 ing sand, and to prevent, as far as possible, the accumulations of 

 air in the mold, which is drawn in during the process of pouring 

 the liquid metal. His sand is made by mi.xing burnt clay with a 

 pulverized sandstone, having a maximum porosity. It has also the 

 fineness of grain, which is essential in producing a delicate mold. 

 An occurrence is related which illustrates the importance of this 

 branch of the art. M. Schott, in explaining the subject to some 

 friends who were dining with him, sent a folded napkin from the 

 table to the foundery, and shortly after showed them a casting 

 which correctly represented the indentations produced by the finely 

 woven thread of the fabric. 



The most important part of the process, however, is the prepa- 

 ration of the metal. M. Schott made a series of experiments to 

 determine the melting point of different kinds of pig iron; and by 

 mixing several in proper proportions, he has been enabled to vary 



