AMERICAN INSTITUTE. 391 



HEIGHT OF CLOUDS. 



Mons. Lias states liis method of measuring the height of clouds. 

 It seems easy to be quite accurate in the angular measurement, as 

 much so as high points on the land. 



Mr. Henry of Flushing, souTin-law of William R. Prince the 

 nursery proprietor, laid on the table handsome specimens of 

 well grown Chinese yams, (dioscorea batatas,) with an account of 

 them carefully prepared by Mr. Prince. 



Mr. Meigs read the paper, as follows, viz : 



CHINESE POTATO— DIOSCOREA BATATAS. 



Few persons are fully aware of the advantages which a study 

 of Chinese horticulture is calculated to impart to our country. 

 The Chinese Empire comprises nearly the same latitudes as our 

 own land, with a climate which, in contrariety to that of Europe, 

 exhibits a mean temperature colder by two degrees in similar 

 latitudes than that of our Atlantic States, as the Isothermal charts 

 of Humbolt reveal to us ; and it therefore offers us productions 

 which must here become readily acclimated. 



The God of Nature has stamped a similarity of character on the 

 vegetable productions of North America and China, far greater 

 and more striking than between any other sections of the globe. 

 More than twenty genera, comprising a vast number of species, 

 are no where found growing naturally on our wide spread earth, 

 save in China and the United States. The magnolia, the glory of 

 our forests, the mulberry, deciduous cypress, aralia tree, gledits- 

 chia, illicium, calycanthus, hydrangea, wistaria, wiegela, scisan- 

 dra, and the panax or ginseng, are confined solely to these two 

 countries, and even the dioscorea is found in no other northern 

 clime. 



Our intercourse with China, until within a few years, has been 

 confined to the port of Canton, a city situated in and representing 

 that strip of China comprised within the tropics ; and even there 

 our encroachments were restricted to a small section of one suburb 

 called the English or Foreign Factory. No stranger was per- 

 mitted to enter the city, much less to penetrate the interior; and 

 any further knowledge was obtained only by stealth and at immi- 

 nent personal risk. 



The productions of the district of Canton are siii generis, and 

 being tropical, are unsuited to our country — the teas and silks, 

 the mighty commercial products of that Empire, being easily 

 transported, are brought to Canton from the interior, thus sup- 

 plying the demands of the commercial world. The tropical sugar 



