AMERICAN INVENTIVE PROGRESS. 241) 



firmly; those of piles were built in deeper water, where the waves would 

 sweep away a foundation of fascines. Lake dwellings as old as the stone 

 age are found in some parts of Russia, and in Borneo and the Malay archi- 

 23elago, as well as in Africa. Herodotus mentions them on Lake Prasias,. 

 in Thrace; and as these were connected with the shore only by a single 

 narrow bridge, the inhabitants were enabled to defy the troops of Darius, 

 Each family occupied one hut, and caught fish by letting a basket down 

 through a trap door. 



In Switzerland, large settlements of lake dwellings have been discovered 

 in Lakes Zurich, Constance, Geneva, J!^eufchatel, and others; and from one 

 in the little lake of Moosseedorf, near Berne, a vast quantity of very inter- 

 esting relics of the stone age have been found, together with weapons and 

 imj)lements made of teeth and horns of animals, and fragments of pottery, 

 A lake village at Robenhausen, in the Canton of Zurich, contains numer- 

 ous dwellings, and it has been estimated that 100,000 piles of oak, beech,, 

 and fir were used in its construction ; and three different sets of piles in- 

 dicate as many different periods of construction. Wheat, barley, burnt 

 apples and pears, beech nuts, cherry stones, fragments of cordage, and cloth 

 of flax and bast, and stone relics, were found here in great profusion. 



Similar structures have been found also in the lakes of Scotland and Ire- 

 land. — ScieMifie American. 



AMERICAN INVENTIVE PROGRESS. 



The future historian of the inventive progress of this country will find 

 that the record of the same naturally divides itself into two distinct parts,, 

 each marking a separate era. These may be termed respectively the period 

 of conception and the period of development. During the former most of 

 the great American inventions were first originated; during the second,, 

 which includes the present time, the tendency of inventors has been more 

 towards seeking new applications lor established principles or improving: 

 upon earlier embodiments of the same. 



The first era begins with the labors of Franklin, Eittenhouse, Hare, 

 Evans, and their contemporaries. It terminates with the end of the ^'•ear 

 1849. Inspection of the records of the Patent Office shows quite- clearly 

 the substantial basis for the division we have suggested. The first patent 

 granted by the United States was dated July 31, 1790, and was issued to 

 Samuel Hopkins for a process of making pot and pearl ashes. During 

 that year the total number of patents Avas but three; the following year it 

 amounted to thirty-three, and then for sixteen years the aggregate fluctu- 

 ated, falling as low as eleven and reaching as high as ninety-nine. For the 

 seventeen years following the variations were between one, hundred and 

 three hundred, the last mentioned number not being exceeded until 1825.. 

 The increase subsequently was more rapid; and by August, 183(3, when the 

 present system of numbering the patents began fit appears with those of 



