AWAEDS OF PKEMIUMS. 65 



of iron. This appears to be accomplished by this new Eod ; 

 for a Eod only three-eighths of an inch in diameter is said to 

 have a conducting surface of about two inches in breadth ; be- 

 ing double that of the ordinary solid rod. 



Few persons are ignorant of the fact that the discovery of 

 this simple means of protection against "the artillery of heaven," 

 was made by our own Franklin ; but many do not fully appre- 

 ciate the more important truth, that the simple experiment with 

 a kite was only one link in the chain of circumstances which 

 led to the invention of the Electro-Magnetic Telegraph of Prof 

 Morse. We are apt to sneer at, and look upon as trifling, the 

 minute investigations of men of science into the laws and mys- 

 teries of the creation ; but we here have an example showing 

 that experiments and researches, apparently the most trifling, 

 may lead to results the most important. It is only by a patient 

 and thorough study of all the laws of nature, and by compar- 

 ing one with another, that important results are brought out in 

 the end. Every step in the way is essential, and if omitted the 

 goal is never attained. 



Lightning Eods are extensively used in some portions of 

 France, under the name of Paragretes, to protect the crops of 

 the farmers from injury by hail ; it being well ascertained that 

 by gradually drawing down the electricity of the clouds, the 

 foiTnation of hail is prevented. Fortunately, although we have 

 hail in Wisconsin, we are not afflicted with so much as to ren- 

 der any such precaution necessary. 



One of the principal causes of f lilure of Lightning Eods to 

 protect our property from electricity, arises from the want of a 

 proper connection at the joints ; any slight interruption in the 

 conducting surface, causing the fluid (if it be one), to pass to the 

 walls, and thus increase, rather than diminish the danger to be 

 apprehended from lightning. The continuous rods exhibited, 

 obviates entirely all danger on this account. 



151.' — [Drawings of the Grasses of Wisconsin, showing the 

 minute structure of the flowers, etc., as well as the general as- 

 pect of the species, made by I. A. Lapham, and intended to il- 

 lustrate his essay on this important family of plants, in the Sd 

 G 



