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Upon the electrical experiments to determine the location of the bullet in the body of the late President Garfield; and upon a successful form of induction balance for the painless detection of metallic masses in the human body . 16 Singularly eiiu«2:li Mr. J. II. C. Watts, in Baltimore, hadiudepeiideiitly arrived at a very similar form of coil, and with the instrument I^ JYg. 11. sliown in Fig. 10he had ohtained atone time a hearingdistance of cm.,(or 8 inches, 1) l)utfrom some causenot ascertained hewas unable subse-(juently to repro-duce the effect. The final formof apparatus ado
Upon the electrical experiments to determine the location of the bullet in the body of the late President Garfield; and upon a successful form of induction balance for the painless detection of metallic masses in the human body . 16 Singularly eiiu«2:li Mr. J. II. C. Watts, in Baltimore, hadiudepeiideiitly arrived at a very similar form of coil, and with the instrument I^ JYg. 11. sliown in Fig. 10he had ohtained atone time a hearingdistance of cm.,(or 8 inches, 1) l)utfrom some causenot ascertained hewas unable subse-(juently to repro-duce the effect. The final formof apparatus adop-ted as the result ofthe above experi-ments is shown in Fig. 11. Withthis arrangement and a bat-tery of six l)ichromate elementsfreshly set up, w^e were always>ure of a hearing distance of atleast 5 cm., although after thebattery had been in use for sometime the hearing distance hardlyexceeded 4 cm. Tlie following-are the dimen-sions of the coils A B (Fig. 11)and their resistance: Coil A Exterual diameter 7 cm. luteriiiil (Tiameter ^-^^ ti»- Depth ^-^ li- Wire used, No. 23, (cotton covered.) Kesistauce, 2 ohms. Coil B External diameter -^-5 cm. Internal diameter ^ • Depth « • Wire used, No. ;}f>, (silk covered.) Kesistance, 75 ohms.
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Keywords: ., bookauthoryapamphl, bookcentury1800, bookdecade1880, bookyear1882