weir site for the periodic delivery of the fuel required by a System 3 

 supply. Local electric power rates, although a consideration of less 

 significance, might also affect the choice of power supply system for 

 a particular weir. 



It cannot be emphasized too strongly that all of the elec- 

 trical devices described in this report are extremely dangerous if not 

 approached and/or handled properly by experienced personnel. Ample 

 opportunity exists for inquisitive persons, not familiar with the 

 devices, to electrocute or at least seriously harm themselves. For 

 this reason, all installations must be adequately fenced in a manner 

 that will discourage curious individuals. So-called "cyclone" fencing 

 surmounted by triple strands of barbed wire is recommended. Generator 

 housings and access gates should be locked and prominent "warning-high 

 voltage" signs posted on all facings of the enclosing fence. In addi- 

 tion, the circuitry of the installation should provide for the operation 

 of several red "warning" lights which can be placed in prominent loca- 

 tions on the suspension towers. 



Acknowledgments 



We wish to acknowledge the assistance of Mr. William L. Stahl, 

 formerly Project Engineer, Cook Research Laboratories, Chicago, Illinois, 

 who contributed materially to the conception and planning of the first 

 electromechanical weir and trap installed in the Ocqueoc River in 195l. 

 During the 1952 season, the following members of the Fish and Wildlife 

 Service, Great Lakes Fishery Investigations, devoted considerable time 

 and effort to the project: Messrs. Leo Erkkila, Clifford Tetzloff, and 

 Joseph Beil at the Squaw Creek installation; Messrs. Leonard Joeris and 

 A. C. Bennett at the Hibbards' Creek and Kewaunee River installations; 

 Messrs. Howard Loeb and Clifford Brynildson at the Carp Creek installa- 

 tion! an <i, Mr. Alberton McLain who aided in devising the electrical bar- 

 rier consisting solely of two submerged electrodes. We are also indebted 

 to Dr. James W. Moffett, Chief, Great Lakes Fishery Investigations, for 

 guidance and aid in the work program. 



Literature cited 



Apple gate, Vernon C. 



1950. Natural history of the sea lamprey, Petromyzon marinus , in 

 Michigan. U. S. Dept. of the Int., Fish and Wildl. Serv. , 

 Spec. Sci. Rep.: Fish. No. 55, 237 pp. 



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