SIZE OF MESH 363 



four thin upright rods. Through eyes in the upper ends of these rods runs a 

 cord, and over the whole structure is placed a box-shaped net. The net sold 

 with the stretcher has its lower margin weighted ; it is intended that this lower 

 margin should lie on the ground. But this is a theoretical arrangement. First, 

 one rarely gets a flat piece of ground free of grass and stones whereon to place 

 the stretcher ; secondly, a sudden gust of wind causes the hanging net to ' ride- 

 up ' on the feet of the stretcher ; and, lastly, a stone or grass lifts up the lower 

 margin of the net. 



" The net, etc., should be arranged as follows : — Take a large, long blanket, 

 7 ft. X 5 ft., fold it lengthways, and lay it on the stretcher to serve as a mattress. 

 Arrange the blankets wliich will cover you just as the top-bedding is arranged 

 for an in-door bed. Tuck in the net carefully all round under the blanket- 

 mattress, taking especial care to cross the folds of the net round the upright rods. 

 Crawl in under the net and close it in the usual way. The stretcher used by the 

 writer, when opened for use, measures six and a half by two and a half feet, and 

 stands fifteen inches above the ground. The whole outfit (stretcher, rods and 

 net) weighs 26 lbs. and can be packed into a canvas sack measuring three feet 

 by thirteen inches." 



The Medical Department, of the TJ. S. Army, is now advising the Quarter- 

 master-General's Department that, in the belief of the experts of the Office of 

 the Surgeon-General, screens with 16 meshes to the inch will exclude the yellow- 

 fever mosquito and the malarial mosquitoes. Col. J. E. Kean has given us 

 this information, and states that this opinion is based upon some very careful 

 experiments made by Doctor Juan Guiteras in 1908. Colonel Kean writes 

 further that Dr. Charles F. Craig, of the Medical Corps, U. S. Army, reports 

 that a 16-mesh to the inch gauze was always successful in excluding Anopheles 

 mosquitoes in the Philippines, and he was stationed at Camp Stotsenburg where 

 these mosquitoes were exceedingly abundant. Since it is known that certain of 

 the anopheline mosquitoes of the Philippines are smaller than species found 

 in the United States, the Surgeon-General of the Army has directed that the 

 Board for the study of Tropical Diseases investigate the question further. 

 Doctor Guiteras's report to Colonel Kean has been sent to us, and we print it 

 as follows : 



" The bronzed wire gauze of 16 threads to the inch that was sent to me by you 

 for trial as to its efficiency in barring the passage of stegomyia mosquitoes, has 

 been subjected to a series of experiments in our laboratory at Las Animas 

 Hospital. 



" I should state that we had heretofore acted under the impression that an 

 18 wire mesh was required ; that we had never employed in this hospital any but 

 the 18 wire mesh, and that this opinion was in part based on experiments that 

 had been made by Dr. Eosenau of the Public Health and Marine-Hospital 

 Service. I do not think, however, that Dr. Rosenau gave his experiments as 

 conclusive. 



" The following equipment was used for our experiments : 



" A large cage or wooden frame, closed in with wire gauze made of 18 threads 

 to the inch. The cage had a double door, and measured 2.10 meters long by 1.50 

 meters wide, and 1.93 meters high. 



" An ordinary wooden tub measuring 0.40 meters in diameter, and covered 

 with bronzed wire gauze of 16 threads to the inch. 



" A small cage measuring 0.54 meters by 0.26 meters by 0.34 meters, con- 

 sisting of a frame covered with wire gauze of 18 threads to the inch. This long 



