CANKEll-WORM. 255 



weeks it was stirred, and in a few weeks afterwards a 

 little more oil was added ; and from the time the oil 

 was first put in until the first of May following, there 

 was a little oil put in twice, and the oil also received 

 two or three stirrings. Putting the oil in three times 

 and stirring it, giving the trees all the attention neces- 

 sary, was less labor and occupied less time than it 

 would have taken to tar the trees for one week. This 

 apparatus destroyed the insects so completely (which 

 for a number of years previous had been so numerous 

 as to destroy the fruit) that it was difficult to find one 

 upon the trees, and the crop of apples was so large as 

 to render it necessary to prop the trees. This appara- 

 tus has many properties to recommend it. It is more 

 eff'ectual, more durable, and cheaper than tin troughs ; 

 it also takes less oil to fill a circular trough than it does 

 a square one, for a tree of the same size. The packing 

 is more easily put in, as the space is of a uniform width 

 around the tree. It is also less liable to get out ; and if 

 the top of the packing was daubed with a little tar, it 

 would stick it together, taking care not to put any of 

 the tar upon the tree or the trough, but only upon the 

 packing. This trough will last many years without 

 being made larger; and, when the tree has grown so as 

 to fill the space that was left between the trough aud the 

 tree, the trough can be cut open, and a piece soldered 

 in, so as to make it large enough for several years more. 

 And if the troughs are ever taken off, the lead will be 

 worth two thirds as much as it was when it was put on. 

 But I should not consider it safe to take it ofi* while there 

 were any canker-worms in the neighborhood, for they 

 have been in some neighborhoods for the last fifty years 

 without intermission, according to the accounts of the 

 inhabitants. Being in conversation with an oil mer- 

 chant, I inquired what kind of oil would remain 

 longest exposed to the air without drying upon the 

 surface : he replied, that cod-fish oil would never dry 

 perceptibly, and for that reason was never used for 



