THE INVEXTUKS OK TlIK TELKGKAPIT AND TKLKl'HOXH. 643 



(ialviliioscopic. or. as tlicy liaxc been more (•(Muinoiily called, iicrdle 

 telegraplis icsnlted vcr> shortly t'i<Mn tlu'sc <lisco\ cries. In iliis field 

 ol" invention we find, prominent among the eail\ woikers, the distin 

 liuished names of .Vin[K'i(', (iauss, and Weber. Am|»ei'e proposed a 

 mnlti])le wire telegraph with iiahanoscope indicators in ISL'O. A modi- 

 tication of Ampere's telegra])h was carried ont by Ititchic. and after- 

 wards exhibited in Edinburgh by Alexander. In this telegra])h thirty 

 wiles were used, twenty-six for the letters of the ali)habet, three for 

 signs of punctuation, and one for the end of a word. The gailvau()Scoi)e 

 needles eaoli carried a snnill screen wiiich in its normal i»osition cov- 

 ei-ed the letter, but which, on the passage of a current through the 

 wire, was drawn aside, ex])osiug the letter t(» \iew. The transmitting 

 keys were arranged like the keys of a piano-lbrte. With the excep- 

 tion of the use of galvanic instead of static tilectricity this telegraph 

 was not much in advance of the pro])Osal of Morrison. A single cir- 

 cuit telegraph was invented in tlie yenv 1828 by Tribaoillet, who also 

 used a galvanoscopt^ as tln^ indicator. 



In 183U, a tive-needU^ telegraph was invented by Schilling, who also 

 used a single needle and single circuit telegraph, using reverse cur- 

 rents and c()nd)inations of signals for an alphabet. Models of this 

 telegraph were made and exhibited before thi' Emperor Alexander 

 and others, but Schilling unfortunately died before any pratrtical result 

 was attained. In 183.), Schilling's telegraph w^as dexeloped to some 

 extent by (iauss and Weber, who used it for ex[»erimental i)uri)oses. 

 The cliief rnodilicat ion introdnce(l by these e\[>erinienters was the snb 

 stitution of induced currents, pro<luced by the motion of a coil of wiie 

 surrounding a bar nmgnet, for the galvanic cnrrejits used by Schilling. 

 The following translation of a |)art of a report of the magnetic observa- 

 tions of these ])hysicists given in Toggandorl's AhikiIcii. \xxii, p. 

 5<58, is (pioted from Sabine's EU'ctrir Tclcf/rKpli: ••There is, in connec- 

 tion with these ai langements, a great and until now in its way novel 

 })roJect, for which we are indebted to Prof. Weber. This gentleman 

 erected during tlu^ past year a. double-w ire line o\er the houses of the 

 town ((r(")ttingen) IVom the Physical Tabinet to the Observatory, and 

 lately a continuation from the latter building to the Magnetic Obser\a- 

 tory; thus an immense galvanic chain (line) is formed, in which the 

 galvanic current, the two multipliers at (he ends being included, has 

 to travel a distance ot' nearly !l.(MK» i Prussian) feet. The line wire is 

 nH)stl\ of copper, of that known in commerce as •No. .'!," of whi(;h one 

 meter weighs eight grams: tiie wire ol the multipliers in the Mag- 

 netic Obser\atory of copper, ■ No. 14.* silvered, and of which one gram 

 measures L'. (I nn-ters. This arrangeim-nt promises to oiler oppoit unities 

 for a number of interesting experinH'tits. We regard, not without 

 ailmiration, how a single pair (tf plates, brongiit into contact at the 

 furthei" end. instant a neonsly communicates a mo\emcnt to t he magnetic 

 bar, which is deliected at om-e for o\'er a thousand di\ isions of the 



