/ 



I 



I 



[Tofacrp(ige3iQ.'] 



Descripiiou. 



netic luiiu (new dotcrminatioi 



i-mng- 1 



itioii) J 



Absolute — ^-^-T-xlO'eleotro-mag- ( 



second f 



nolic units (old dettfrminatioD) J 



Twenty-fire feet of a eortain oop- ' 

 per wire, weighing iH5 grains . . . _ 



Absolate j xlO^electro-mag- 



netic unite determined bj Webor 

 (1862) 



One meli» of pure mercury, one! 

 square millmietr* section at 0° C J 



One metre of puiw mercury, onel 

 square millimetre soctiun at 0'' C. J 



One metre of pure mercuiy, one! 

 square millimetre section at t^^ C. J 



British Aasociation unit , 



millimetres in diameter (tempe- 

 rature not known) J 



One kilometre of iron wire, four) 

 millimetres in diameter (tempo- t 

 rature not known) J 



One kilnroetie of iron wire, four | 

 millimetres in iliameter (tempo- I 

 rature not known) | 



One English standard mile of pure "] 

 annealed copper wire -j^ in. dia- ^ 

 meter at io\>C J 



One English standard mile of one 1 

 special copper wire -^ inch in y 

 liiamcter J 



One German mile=S238 yards of] 

 iron wire ^ inch in diameter V 

 (temperature not known*) J 



Thomson's unit - 



Weber's absolute 

 metre 



second 



XlO' - 



Siemens 18G4iiSiie — 

 Siemens (Berlin) --.. 



Siemens (London) .... 

 B.A. unit, or Obmad. 



Kenty 



Brunei 



Swiss 



^ttliiessen.... 



Varley 



Qennan mile . 



Absolute 

 foot , .^, 



1000 

 1O505 



3138 

 3156 



3621 



30-40 

 32-03 

 M-2I 

 44-57 

 Si-01 

 1884 



Thomson's 

 old unit. 



0!)520 

 lOOO 



3004 

 3-010 

 3-123 



28'94 

 3050 

 32-56 

 42-43 

 79-96 

 179-4 



Approxiiiifitt? Relative Values of varioua Units of Electrical Eesietanco. 



0-4788 

 0-5029 



1-000 



1-503 

 1-511 



14-50 

 15-J4 

 16-38 

 21-34 

 40-21 

 90-22 



Weber's 



absolute 



metro „,n- 



0-3316 

 0-3483 



0-0026 



1-041 

 1-046 



10-08 

 10-62 

 11-34 

 14-78 

 27-85 

 62-48 



Siemens 1664 

 issue. 



0-3187 

 03343 



0-C6D5 



1-000 

 1-005 



i'04se 



00968 

 10-20 

 10190 

 14-19 

 2075 

 6003 



Siemens 

 (BerUu). 



0-3108 

 0-3328 



0-0018 



0-9950 

 I -000 



1039 



9-634 

 10-15 

 10-84 

 14-12 

 2661 

 69-71 



Siemens 

 (London). 



03131 

 03289 



0-0640 



09829 

 09881 

 1-000 



1-026 



9-520 

 1013 

 10-71 

 1395 

 26-30 

 69-00 



B. A. unit, or 

 Ohmnd. 



0-3018 

 0-3202 



0-6367 



0-9503 

 0-9625 

 09742 



1-000 



9266 

 9-760 



10-42 



13-69 



25-01 



67-44 



Digney. 



0-03289 

 003455 



0-0C8C9 



01033 

 0-1033 



1-000 

 1-054 

 1-125 

 1-6(3 

 2-763 

 6-198 



Br&iiiGt. 



0-03123 

 0-03279 



0-06620 



0-09799 

 009852 

 0-0997 

 01024 

 0W91 



imo 



1-068 

 1391 

 2-G23 

 5-882 



0-0-2924 

 003071 



0-06100 



0-09177 

 009227 



0-09337 



0-0959 



0-8889 

 0-9365 

 1-000 

 1-303 

 2456 

 5-609 



00-2213 

 002357 

 0-01680 



0-07047 

 007081 



00736 



0-6822 

 07187 

 0-7675 

 1-000 

 1885 

 4-228 



Varley. 



0-01190 

 001251 

 0-2486 



Ofl3737 

 003757 



0-3620 

 0-3814 

 0-4072 

 0-5306 

 1-000 

 2-243 



I 



German 



Miles. 



0005307 

 0005574 



9'01108 



0010G6 

 001675 

 001095 

 001741 



01613 

 01700 



0'1815 

 0-2365 

 0-H57 



I'OOO 



Ot^Mnations. 



Calculated from tlieB. A. unit. 



No measurement made; ratio be - 

 cobi taken rrom'-Webee.aj 

 Ueawemont taken from a deler ■ 

 ^malminiffi2ofa,tandaril 

 «'ntbyProf.Tlioineoi,;doernotl 

 ■'g«e;nthWeber'so..„n,««>S-' 

 mont of aiemena's units ; by We-' 

 Mr 1 Sicmens'a unit = I ■025x 10' 

 metrea-sccond. 

 Measurement, taken from Ibri^ecoil, 

 1. '»sued by Uesara. Siemens 

 r Measuremenl taken from eoiU ndii. 

 1 ^'^,"1 18C2 by Me««. Siemens 

 |_ Halate & Co. (weU adjusted). 

 r Measurement taken from coiU ei!u. 

 i biled in 18(J2 bj Mewre. Siemens, 

 |_ Hakke & Co. (well ndjiuted). 



f Equal to 10,000,000 ^^^^ ac 

 > second 



cording to erperimenla of Stand. 

 L ard Committee. 



r From coils edubited in 1662 (pretty 

 { weUadjusled). 



f From coils wthibited in 1862 (ii 

 \ differently adjusted). 



f From coils exhibited in 1662 (badly 

 L adjusted). 



fFrom a coil lent by Dr. Matthi«- 

 L reri (of Germun-silTer wire). 



' From coils lent b 

 B<^usted], 



f From coils eihibit«d 



\ Meiers. Siemens, Halabe & Co. 



Mr. Varley ■( well 



• Messrs. Siemene do not now manufacture coils with this unit, which ha« been abandoned by them in favour of Iho mercury unit given aboro. 



