the reeds very easil;'' pile up in front. In spite of a recently added protection basket, 

 the Three Star requires a man to continually remove reeds. Thus the machine requires the 

 services of three men. 



Jig. 4.7. Three Star reed mowing machine (Model of 1930). To the 

 left at the front end are the movable oblique beams, between 

 which and under water the mowing comb is located. In the 

 center, the motor, right at rear end the paddle wheels and rudder. 



The fastening of the cutting beam to a central lever and the attachment of a vertical 

 cutting arrangement as is to be found on almost all French machines, according to Roehler, 

 is perhaps a forward step for the future. These vertical finger beams which are attached 

 both in front and behind, cut all cross laid already cut reed stalks in two. 



Similar to the Three Star, but more easily transportable and dipping somewhat less, 

 that is, only about 15 centimeters (about 6 inches), is the motored reed mower machine 

 "Master" . The Llaster according to its size is provided with a 12 or 6 horsepower E.K.TT. 

 gasoline motor or with a crude oil motor. According to statements of the manufacturer 

 it cuts about U hectares (about 10 acres) a day, the total costs per hectare mowing 

 work amounting to 1.2 marks (11 l/2 cents per acre). 



The French machines are furnished ivith two wheeled carts which can be run into the 

 water and under the machines. Such an arrangement is extremely valuable, as the apparatus 

 can be quickly transported from one pond to another. 



To be finally mentioned are the Dr. &igel reed cutting machines which have not been 

 introduced to a larger extent, and which (according to Nanz) have a lateral back and 

 forth moving knife, and the Frank reed roller which, according to Blohm, sei*ves to break 

 the reed stalks. 



The driving in of cattle is likewise a good vfay to eliminate over-water plants, 

 since the animals trample the roots and eat the stalks. In larger fisheries the applic- 

 ation of that sort of remedy is mostly unimportant. 



An elimination of filamentous algae, which can be of importance in trout ponds, is 

 only practicable by pulling them out by using rakes, linen weighted with stones, or nets, 

 etc. Unfortunately the effect lasts only for eight to fourteen dajrs. The combating of 

 algae vdth copper sulphate, should have a concentration varj'ing from 1:10,000 to 

 1:5,000,000, according to the species of algae. Ebeling (according to Czensny) however, 

 found that a dilution of 1:2,000,000 (0.5 milligrams of copper sulphate per liter) 

 reacts i'atally on rainbow trout. The solutions must at least not be left in the pond 

 unchanged for any length of time. Injuries to the trout would be unavoidable. Carps 

 are far more resistant. 



157 



