1178 



Canadian Forestry Journal, June, 1917 



New Devices in Protective Work 



By COERT DUBOIS, 



U. S. Forest Service 



About a year ago there came across 

 my deck a newspaper clipping about a 

 small wireless apparatus operated by 

 the power generated by four dry bat- 

 teries, invented by one Dr. H. Bar- 

 ringer Cox, of Bedford Hills, New 

 York. On a chance I wrote Doctor 

 Cox of our interest in a low-power 

 wireless, described our communica- 

 tion problem in protection work, and 

 asked him what he had. He, in turn, 

 was so interested in the project of 

 developing his invention in co-opera- 



tjon with forest protection work that 

 he packed up and came out to Cali- 

 fornia. He arrived last January, and 

 established his laboratory and work- 

 shop on a canyon ranch in the Santa 

 Barbara National Forest. 



The essentials of Doctor Cox's 

 system are what he calls the sending 

 and receiving "loops:" these corre- 

 spond to the aerials in wireless tele- 

 graphy, and, as finally worked out, 

 consist of two 2-inch galvanized iron 

 pipes about 30 feet high, set upright 



•^ D^^m a^^u ^^B n^^DB^^ ■■ 



Try This Stump Pullet^ 

 at Our Risk ^^-^ -«'^'t>^-B-t-p.j"'i!r 1 



YALE UNIVERSITY 

 FOREST SCHOOL 



New Haven, Connecticut, U.S.A. 



YALE University Forest School is a 

 graduate department of Yale Uni- 

 versity. It is the oldest existing forest 

 school in the United States and exceeds 

 any other in th« number of its alumni. A 

 general two-year course leading to the 

 degree of Master of Forestry is offered to 

 graduates of universities, colleges and 

 scientific institutions of high standmg, and, 

 under exceptional conditions, to men who 

 have had three years of collegiate training 

 including certain prescribed subject*. Men 

 who are not candidates for the degree may 

 enter the school as special students, for 

 work in any of the subjects offered in the 

 regular course, by submitting evidence that 

 wUl warrant their taking the work to their 

 own advantage and that of the School. 

 Those who have completed a general course 

 in forestry are admitted for research and 

 advanced work in Dendrology. Silviculture, 

 Forest Management, Forest Technology and 

 Lumbering. The regular two-year course 

 begins the first week in July at the School 

 camp, Milford, Pennsylvania. 



For further information address 



JAMES W. TOUMEY, Director 



New Haven - Connecticut 





TREES, SHRUBS AND SEEDS 



Hardy Northern Trees and Shrubs at Lowest 

 Prices. Native and Foreign Tree Seeds 



EDYE-DE-HURST&SON.DENNYHURST 



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4* * 



Hill's Seedlings and Transplants 



ALSO'Tree Seeds for Reforesting. Best foi; over 

 half a century. Immense stock of leading 

 hardy sorts at low prices. Write for price list and 

 mention this magazine. 



Forest Planters Guide Free. 



The D. Hill Nursery Co , Evergrben Specialists 



Largest Growers in America. 



Box 503 Dundee, 111., U.S.A. 



_« „ « 4. 



PERFECTION SLEEPING BAG 



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