34^ Report of the Horticultural Department of the 



commonly used metals of ordinary pumps. Neither should leather 

 or rubber valves be used. This is important. The valve used in 

 the better class of spray pumps is a brass valve ground to fit its seat 

 perfectly. Some pumps are made with removable brass lining, per- 

 mitting the quick replacing of a worn lining with a new one. In 

 order to facilitate taking a pump apart and cleaning it, the working 

 parts should be readily accessible. 



Single-acting pumps. — The simplest single-acting pumps have but 

 one set of ports or valves. The cylinder is emptied and at the same 

 time filled by the upward, or backward, stroke of the plunger ; it 

 remains filled during the return stroke, the plunger passing through 

 the liquid, as in the common pitcher pump, and is again emptied and 

 filled at the next upward, or backward stroke. The typical double- 

 acting pump, on the other hand, is provided with at least two sets 

 of ports or valves. The cylinder is filled from one end at one stroke 

 and emptied at the return stroke of the plunger, filling at the same 

 time from the other end. 



Some single-acting pumps have the cylinder submerged in the 

 liquid while others have the cylinder placed on the outside of the 

 tank or barrel. The latter are too well known to need description. 

 Among pumps having the cylinder on the outside of the barrel are 

 several made by W. and B. Douglas (one of them is shown in Fig. 

 19), the Deming Go's. Gem, Simplex (Fig. 20) and Peerless, and 

 the Field P'orce Pump Go's. Empire Queen, Empire King (Fig. 21) 

 and Empire Junior. Pvnnps of the submerged cylinder class, that 

 is, pumps which are near the bottom of the barrel or tank and sub- 

 merged in the liquid, have certain peculiar merits. From their loca- 

 tion they can use simpler valves, they never need priming as the 

 valves are always flooded and there are no projecting parts to catch 

 on limbs. Most of the pumps of this class are made with short 

 cylinders, but a few have long cylinders. Among such are the De- 

 fender (Fig. 22) and the Little Giant of J. F. Gay lord, and the 

 Myers brass barrel pump. To the class of inside pumps with short 

 cylinders belong Morrill and Morley's Eclipse (Fig. 23), the Myers 

 Improved brass barrel pumps (Fig. 24). Goulds' Pomona (Fig. 



