RADIOTELEGRAPHY—FLEMING, 183 
Time does not permit of the discussion of the many other points in 
connection with radiotelegraphy and telephony which have been the 
subject of recent work. Much attention has been paid lately to 
methods of cutting out atmospheric signals due to natural electrical 
discharges in the atmosphere, which are troublesome disturbers of 
the etherial calm necessary for radiotelegraphy. Considerable 
thought and expenditure have been necessary to discover means for 
overcoming the difficulties of long distance transmission by daylight, 
and also those arising from the cross talk of other stations. Much 
also has been done in training skilled wireless operators both in the 
navy and for the mercantile marine work. Radiotelegraphy, like 
aviation, 1s an art as well as a science, hence personal skill is a factor 
of importance in turning the flank of the difficulties of the moment. 
Nevertheless, the art and the science of radiotelegraphy are both 
progressing, and the splendid services already rendered by it in sav- 
ing life at sea are at once a proof of present perfection and an evi- 
dence that the arduous labors of investigators and inventors have 
borne fruit in yet larger powers to command the great forces of 
nature for the use and benefit of mankind. 
45745°—sm 1909——13 
