GE031F.1RA DEKOJUAKIA. 177 



at short intervals, it is evident thai the expense must increase in a great- 

 er ratio than the depth. 



The most unpleasant circumstance attendant upon this business is 

 the occasional breaking of a rod, a portion of which remaining at the 

 bottom of the well, is an effectual barrier to all further progress until it 

 is removed. To accomplish this implements of various forms have been 

 designed, sometimes the workmen liave succeeded in cutting a screw 

 upon the end of the broken rod, and removing it by the attachment of 

 other joints, but from the small size of the excavation, and the great 

 deptla to which it is sometimes carried, it is evident that sucli an achieve- 

 ment must be regarded as a triumph of mechanical skill. 



It frequently happens that streams or films of impure water are pass- 

 ed through before reaching a stratum of the desired quality ; to prevent 

 the mixture of those waters, and also to protect the well from rubbish, 

 the interior must be lined with a metallic tube. 



The height to which the water will rise in these wells depends of 

 course, upon the level of the source from which it flows. Sometimes 

 the pressure is sufficient to throw a constant stream several feet into the 

 air. Sometimes too it does not rise to the surface, and a well of the or- 

 dinary kind must be dug to meet il, and a reservoir in which a sufficient 

 quantity can be retained for use. Common wells may be occasionally 

 improved by boring holes in the bottom on the artesian principle. 



The temperature of the water of artesian wells is very uniform, and 

 is proportioned to the depth to whicli tliey penetrate. This fact is used 

 in support of the theory of central heat. H. H. 



GEOMETRA DEFORIARIA. 



At the meeting of the Cincinnati Horticultural Society, on Saturday 

 the 21st of last month, the following communication was read by Mr. 

 Edward J. Hooper, one of the Editoi-s of the Western Farmer and Gar- 

 dener. We learn from the Cincinnati papers, that this insect has been 

 very destructive in that region, devastating the orchards far and wide. 

 On both sides of the Ohio, whole orchards have been stripped by it of 

 their leaves, and look as brown and naked now as they did in January. 

 lis ravages are not confined to apple trees, but it has also attacked cher- 

 rv and plum trees surrounding dwelling houses, and isolated elm, locust, 

 and other shade trees standing in open fields. 



"This moth comes out of the earth, according to IVIolIar, an Austrian 

 writer on destructive insects, in the beginning of winter, and seeks out 

 a fruit tree, like the green winter moth, to lay her eggs on. Tiie male 



