Lord Kelvin Mirror Galvanometer Atlantic Cable Vintage Trade Ad Card

Description

Lord Kelvin Mirror Galvanometer Atlantic Cable Vintage Trade Ad Card
NOTE:
THESE ARE NOT POSTCARDS
THEY ARE TRADE/ADVERTISING CARDS.
THEY ARE MUCH SMALLER THAN A STANDARD POSTCARD
AND
THERE IS ADVERTISING TEXT ON THE BACK!
THE CARD DIMENSIONS ARE APPROXIMATELY
2 5/8 '' x 1 3/8 ''  or  6.5 cm. x 3.5 cm.
THIS IS AN ORIGINAL VINTAGE TRADE  ADVERTISING CARD
ATLANTIC CABLE KELVIN GALVANOMETER THOMPSON
The mirror galvanometer was later improved by William Thomson, later to become Lord Kelvin. He would
patent the device in 1858.
Thomson reacted to the need for an instrument that could indicate with sensibility all the variations of the
current in a long cable. This instrument was far more sensitive than any which preceded it, enabling the
detection of the slightest defect in the core of a cable during its manufacture and submersion. Moreover, it
proved the best apparatus for receiving messages through a long cable.
NOTE:
THE REVERSE SIDE HAS TEXT ABOUT THE IMAGE ON THE FRONT SIDE
THE CARD DIMENSIONS ARE APPROXIMATELY
2 5/8 '' x 1 3/8 ''  or  6.5 cm. x 3.5 cm.
NOTE:
THE IMAGE ABOVE IS LARGER THAN THE CARD
TO SHOW THE DETAIL.
SEE SCALED IMAGE ABOVE.
THIS CARDS IS NOT A MODERN REPRODUCTION
IT IS AN ORIGINAL VINTAGE CARD
IT IS NOT PERFECT AND THIS CARD MAY HAVE ONE OR MORE OF THESE:
SLIGHT PAPER LOSS
SMUDGING
ROUNDED CORNERS
SURFACE CREASE
SEE THE IMAGES ABOVE!
10
WE COMBINE SHIPPING
BUY 1 TO 4 TRADE ADVERTISING CARDS AND THE TOTAL TO SHIP IS
BUY 5 TRADE ADVERTISING CARDS AND SHIPPING IS FREE
NOTE:
ON LARGER INTERNATIONAL ORDERS WE MAY REQUIRE REGISTERD
MAIL AND WILL SPLIT THE COST WITH THE BUYER.
INQUIRE IF CONCERNED!