28 



damaged by two-tenths, and these but slightly. The cabbage is dam- 

 aged by a iirolonged spraying of two-tenths, but is not damaged if only 

 enough at two-tenths is put on to cover well. Practically no tree 

 foliage is damaged by an application of even three-tenths, but bey^ond 

 this the foliage is injured. 



Mr. C. M. Weed read the following paper, exhibiting the apparatus 

 described : 



A MODIFICATION OF THE KEROSENE KNAPSACK SPRAYED. 



By Clarence jM. Wee-d, Durham, X. H. 



[Author's abstract.] 



The author reported a series of tests of the knapsack sprayer with 

 kerosene attachment, vshowing that the principal machine now on the 

 market is unreliable in its present form. The chief source of error 

 appears to be due to the continual differences of level in the kerosene 

 and water tanks. To avoid this a kerosene attachment had been made 

 at the New Hampshire Experiment Station, and was exhibited, of the 

 same height as the water reservoir and holding one-tenth as much. 

 A stopcock with a single hole one thirty-second of an inch in diameter 

 connected the kerosene reservoir with the pump. By this arrangement 

 a fairly constant spray having 9 per cent of kerosene in it was obtained. 

 The opinion was expressed that to get successful results we must aban- 

 don the idea of having a large range of variation in one combination of 

 reservoirs — i. e., in expecting to get either a 5 per cent or a 30 per cent 

 emulsion by turning a stopcock at a less or greater angle. The author 

 believed that the kerosene spraj-er was capable of great improvements 

 along the lines indicated, and thought it too great an advance in methods 

 of insect warfare to be lightly abandoned. 



The following communication, by Mr. J. M. Aldrich, was in the form 

 of a letter to the secretary, accomj^anying a working samj^le of the 

 apparatus. The apparatus itself and the manner of working it were 

 described by the secretary with the aid of blackboard illustrations. 

 The following is an abstract of the letter: 



SPRAYING WITHOUT A PUMP. 



By J. M. Aldrich, Moscow, Idaho. 

 [Abstract from letter describing the device.] 



The spraying device which was suggested by the author to the asso- 

 ciation last year (Insect Life, vol. iii, p. 114) is again presented to call 

 attention to two changes in the machine from the first idea. First, it is 

 necessary that the stream from the hydrant enter the lance within 



