Though the honor of inventing the art of wireless telegraphy is generally ascribed to Marconi, this is to give him more credit than he deserves. The principles involved were discovered by others and the utmost done by him was to invent a practical method of applying them. There are other systems of wireless telegraphy of later invention than that of Marconi, through a different application of the same principles. Messages have been sent to enormous distances, far surpassing the width of the Atlantic, as from Nova Scotia and Ireland to Argentina, a distance of 5,600 miles. Under exceptional conditions a distance of 6,500 miles has been attained, but the daily effective range of the best equipped stations is little over 3,000 miles. For overland messages the limit of distance is about 1,000 miles. There are a number of kinds of interference which arise from electrical disturbances in the earth’s atmosphere. A flash of lightning is liable to give rise to a wave of enormous power which will set half the aerials on the earth vibrating in spite of the differences of pitch to which they are tuned. Thunderstorms are at their worst in the summer in temperate latitudes, but they occur to some extent all the year round, and those in the tropics are of extreme violence. As a consequence it is frequently almost impossible to decipher earthly messages owing to the imperious signals from the clouds. Of the various methods adopted for choking off the “atmospherics,” as the disturbances are called, one is to use receiving circuits which respond only to a narrow range of oscillations very different from those produced by a lightning flash. The employment of a high-pitched musical note in the telephone is also an advantage because its extreme regularity distinguishes it from the marked irregularity of the stray waves. [Illustration: WIRELESS STATION ON A STEAMSHIP] On the palatial passenger steamers that plow the Atlantic the Marconi apparatus enables the travelers to keep in touch with their friends, to transact important business on either side of the water, and to secure a continuity of life which was formerly divided by a sea voyage. All the larger vessels now publish a daily paper on board, the news in which has been supplied by the same agencies who feed the newspaper on land. Information is flashed to meet or overtake the vessel and caught up by her aerial, as she pursues her way at twenty-five or thirty miles an hour.