GRAVITATIONAL; SIFTERS. 805 



have been patented that apply the ])owdor by means of revolving per- 

 forated cyliuders. The oldest of tliese seems to be one invented by Mr. 

 William T. Eobiuson, of Huntsville, Tex. (patent No. 14G205, Janutiry 

 0, 1874). It combines both sprinkling and dusting, in that pure water 

 is sprinkled over the plants by an arrangeiuent in front of a two- wheeled 

 truck, while at the same time the powdered poison is dusted from re- 

 volving cylinders attached to the rear part of the truck. The powder 

 thus sticks to the leaves and may be applied at all hours of the day. 

 Both the duster and the sprinkler can be detached at will and used sep- 

 arately if necessary. 



''From Plate LVII, Figs. 1 and 2, the former of which is a plan view, the latter a 

 longituclinai sectional view of the machine, it wnll be seen that the dusting apparatus 

 consists of an horizontal shaft, G, extending each way beyond the wheels, for reaching 

 over the outside rows, and carrying three or more revolving screens or sieves, H, for 

 sprinkling on powdered substances. Said shaft is mounted on the rear end of the 

 frame, I, which is joined to the truck at, J, and suspended from the frame, M, by ropes, 

 L, which are wound upon the shaft, N, or let out from it to shift the screens accord- 

 ing to the height of the plants. The shaft is revolved by a belt, O, from one of the 

 wheels of the truck working on cone pulleys, P O, for varying the speed of the screens 

 or sieves, as may be required. The pulley, O, on the shaft, G, connects with it by a 

 clutch, R, which is connected with a shifting-lever, S, for throwing the shaft out of 

 gear when turning around at the end of the rows to save waste of material. T is a 

 box for carrying the stock of powder from which to replenish the screens or sieves 

 as they become exhausted from time to time. This box may be also used for a seat 

 for the driver. The sieves are supplied through an opening in the ends, which may 

 be closed by a gate or door of any kind, or by an opening in the side similarly closed. 



" The Davis Buster^ invented by Mr. Nicholas A. Davis, of Eusk, Tex. 

 (patent l^o. 154051, September 1, 1874). This is almost an exact coun- 

 terpart of the foregoing machine, but without the sprinkling attach- 

 ment. The only peculiarity is the addition of springs to the revolving 

 cylinders to prevent too great a discharge of the poison in case of a 

 sudden jar. 



" Plate LVII, Figs. 3 and 4, represents the invention attached to a cart. Fig. 4 is a 

 cross-section through the line y y. 



" A represents an ordinary farm-cart, across the rear end of which is secured the hori- 

 zontal shaft, B, having its bearings in the arms, c c, projecting behind the cart. On 

 the shaft, B, are placed two or more loosely-revolving perforated cylinders, E, being 

 revolved upon the shaft, which carries a pulley, a, over which a band or cord works, 

 passing to the hub of the cart-Avheel, from which it receives motion, and thus causes 

 the shaft, B, to revolve w^hen the cart is in motion. Attached to the inner end of each 

 of the outside cylinders is a spiral spring, h, coiled around the shaft, A, and so arranged 

 as to secure an easy, gentle, lateral motion to the cylinders in case of a sudden jar 

 given the machine. A similar spring may be used at the opposite end of the cylinders, 

 so as to check the jar in both directions. This invention can be fixed to any kind 

 of frame moving on wheels, and by a hand-crank and ordinary cog-gearing be suc- 

 cessfully worked. 



" The Levy Buster. — This duster, patented by Mr. Charles H. Levy, of 



Katchitoches, La. (^o. 154690, September 1, 1874), also distributes the 



poison by means of revolving cylinders which can be adjusted to the 



height of the plant. The whole apparatus can be secured to the forward 



63 CONG 20 



