New York Agricultural Experiment Station. 371 



every three weeks. This is also true, of course, of hand pumps, but 

 in this case the wearing does not proceed nearly as rapidly. This 

 wearing' may be prevented to a great extent by care in placing the 

 packing, in selecting the quality used and also in selecting the lubri- 

 cant. In our experience braided hemp packing thoroughly filled with 

 tallow and graphite has given the best service on the piston rod. 



The gland nut on the piston rod should not be screwed up too tight 

 at first, as the heat generated by friction causes the packing to ex- 

 pand. 



We have not yet found any satisfactory material for packing the 

 piston itself. ■Manufacturers have sent out a leather packed piston 

 which it is thought will do much to remedy the trouble of wearing. 

 But so far as we know, this piston has not yet been sufificiently 

 tested in practical work to permit of passing on its merits. 



Oil cups. — There is frequent complaint also of trouble with oil 

 cups. In fact some persons who have operated steam outfits declare 

 they have more trouble with oil cups than with any other part of the 

 outfit. This is a rather surprising experience. Of course, an oil cup 

 needs reasonably skillful handling and the oil must be of good quality. 

 Oil cups sometimes become clogged with thick matter in the oil or 

 with particles of waste used in wiping. All dirt should be kept out 

 of the cup. • But nevertheless if it is rather cold the oil will get thick 

 and not flow readily. In this case it should be warmed. 



Cleaning boilers. — Most of the boilers used in spraying outfits are 

 of the upright type and as such require peculiar management. Sedi- 

 ment and scale form in them quickly, and if not promptly removed, 

 serious injury is likely to result. Flues where exposed to fire should 

 be cleaned of soot every once or twice a week, and oftener if soft coal 

 is used as fuel. A quarter of an inch of soot reduces efificiency nearly 

 one-fourth. The tubes should be cleaned of sediment and lime as 

 often as is necessary. When using some kinds of water a small quan- 

 titv of soda ash is useful as a solvent for lime incrustations ; with 



