_Experiment 4th.--Plates 7 square inches, conducted as No. 1._ -------------+-----------+------+------+------+------+------+------ Distance from| Distance | 1st | 2d | 3d | 4th | 5th | 6th bank to bank.|along shore|Trial.|Trial.|Trial.|Trial.|Trial.|Trial. -------------+-----------+------+------+------+------+------+------ 1 | 1 | 5° | 5° | 5° | 5° | 3° | 3° 1 | 2 | 15 | 14½ | 14 | 15 | 15 | 12 1 | 3 | 17½ | 18 | 17½ | 17½ | 18 | 17 1 | 4 | 18 | 18 | 18 | 17½ | 17½ | 17 -------------+-----------+------+------+------+------+------+------ The distance from bank to bank, 30 inches. Depth of water, 12 inches. In experiment 4, the liquor of the batteries was very weak, exhausted towards the last; and in trials 5 and 6, the irregularities are to be attributed in part to the weak liquor, and in part to the twilight hour at which the experiments were made. As the result of these experiments, it would seem that there may be situations in which the arrangements I have made for passing electricity across the rivers may be useful, although experience alone can determine whether lofty spars, on which the wires may be suspended, erected in the rivers, may not be deemed the most practical. The experiments made were but for a short distance; in which, however, the principle was fully proved to be correct. It has been applied under the direction of my able assistants, Messrs. Vail and Rogers, across the Susquehanna river, at Havre-de-Grace, with complete success; a distance of nearly a mile. TELEGRAPHIC CHESS PLAYING In order to give some idea of the accuracy with which the telegraph transmits intelligence, we here give two games of chess, as played by distinguished gentlemen in Baltimore and in Washington. The two games are selected from the seven played. The number of moves made in playing the seven games, were 686, and were transmitted without a single mistake or interruption. The Baltimoreans played with the white pieces, placed on numbers 57, 58, 59, 60, 61, 62, 63, and 64, figure 32. They were commenced November 16th, 1844. B, Baltimore; W, Washington. [Illustration: FIG. 32.] _First Game of Chess._