130 ANNUAL OF SCIENTIFIC DISCOVERY. 



IMPROVEMENTS IX TELEGRAPHIC APPARATUS. 



Several improvements in the operation of the Morse telegraph have re- 

 cently been completed in England. One by the brothers Disney marks the 

 characters with ink, instead of simple indentation in the paper. This is a 

 relief to the eyes of the operator, and an additional guaranty of accuracy. 

 This is accomplished by making immovable the instrument for tracing, which, 

 is a simple desk turning upon itself; the lever, moved by electricity, has no 

 other function than to press the paper against the desk at divers intervals 

 and for different lengths of time. By a clockwork movement this little desk 

 rubs constantly against an clastic roller saturated with a fat ink, which long 

 preserves its fluidity, so that it suffices to put a few drops of it every two or 

 three days on the surface of the roller. This improvement has been adopted 

 on the lines in France and Belgium. Mr. Wheatstone, of England, has also 

 invented a convenient process for increasing the speed of transmission by 

 the Morse instrument, similar to a process for the same purpose connected 

 with the Bain instrument. A prepared paper is punched with holes corres- 

 ponding to the Morse characters, and the message thus prepared is placed on 

 a moving metallic band, and is made to take the place of aii operator and 

 transmit itself. 



L. Bradley, of New York, has patented an improvement in telegraphing by 

 sound, by which he dispenses with the local batteries of the House system. 

 The magnet and armature are placed in the main circuit, and by a simple 

 combination of sounding-board and overstrung wires the indistinct tick is 

 expanded to a clear, sharp, and perfectly intelligible knock, which the ope- 

 rator can follow with perfect ease and certainty. Each knock is loud and 

 abrupt, and there is not the slightest liability of running them together, 

 however rapid the manipulations of the operator. 



MAGNETISM AND THE MOOX. 



At the American Association, 18GO, Professor Bache presented a paper on 

 the attempt, from observations at Girard College, to determine the effect of 

 the moon upon the daily movements of the magnetic needle. The observa- 

 tions and calculations of European magnetic observers have shown that 

 such an effect is produced. The Philadelphia observations were divided into 

 three groups, and the curves of each group were found to agree with each 

 other, and with the results of General Sabine and others. Fourteen minutes 

 after the moon is on the meridian, the needle is eighteen-hundredths of a 

 minute westerly of its position, and six minutes after the moon passes the 

 lower meridian, twenty-three hundredths of a minute west; while about 

 moon-rise and moon-set the needle is nearly as much east of its position. 

 There is also a slight single movement between two successive culminations 

 of the moon, just as there is a daily, as well as a semi-daily, lunar tide in the 

 ocean. Further examinations show a greater effect of the moon in summer 

 than in winter. Moreover, it appears that the effect is probably greater at 

 new moon than at full, and greater when the moon is north of the equator 

 than when south. The effect when the moon is near the earth is greater 

 than when she is at a greater distance. But it must be remembered that all 

 these effects are exceedingly small. 



