Report of the Annual Meeting Volume 1861 (Paperback)


This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1862 Excerpt: ... the acts of making and breaking contact could possibly have in common. I reflected that when two wires are approaching or receding, they equallv pass through points at every possible distance (within limits) one from the other. Thus I thought that the relative distance between the two wires might be the peculiarity which, being common to the two acts, might produce similar effects in each case. 1 therefore tried the effect of a loose contact Detween the two wires, resting the one wire very lightly on the other, instead of pressing or pulling the two together; a permanent current was at once produced, Bo strong as to hold the deflecting magnet of the galvanometer against its limiting steps. I then introduced resistance coils into the circuit for the purpose of reducing the deflection, but to my surprise it was not until I had added a resistance equal to that of 2000 miles of the Red Sea cable, or about 1000 miles of the common No. 10 copper, that I reduced the deflections within tho range of my galvanometer. The current could be maintained through this resistance for twenty minutes at a time--not perfectly constant indeed, but not wavering more than was inevitable from the varying pressure given by the hand to the two wires. The current was strongest when one end of the wires was white-hot, the other being dark red. I varied the experiment in many ways, using different galvanometers and different copper wires, mit always with one result. A tight contact gave a barely sensible current; a loose contact gave a current which could be maintained permanently equal to that which would be produced through a similar resistance by the eighth or tenth part of a Daniell's coii, --a strength sufficient to signal through a cable to America, if ever one be laid. I next tri...

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Product Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1862 Excerpt: ... the acts of making and breaking contact could possibly have in common. I reflected that when two wires are approaching or receding, they equallv pass through points at every possible distance (within limits) one from the other. Thus I thought that the relative distance between the two wires might be the peculiarity which, being common to the two acts, might produce similar effects in each case. 1 therefore tried the effect of a loose contact Detween the two wires, resting the one wire very lightly on the other, instead of pressing or pulling the two together; a permanent current was at once produced, Bo strong as to hold the deflecting magnet of the galvanometer against its limiting steps. I then introduced resistance coils into the circuit for the purpose of reducing the deflection, but to my surprise it was not until I had added a resistance equal to that of 2000 miles of the Red Sea cable, or about 1000 miles of the common No. 10 copper, that I reduced the deflections within tho range of my galvanometer. The current could be maintained through this resistance for twenty minutes at a time--not perfectly constant indeed, but not wavering more than was inevitable from the varying pressure given by the hand to the two wires. The current was strongest when one end of the wires was white-hot, the other being dark red. I varied the experiment in many ways, using different galvanometers and different copper wires, mit always with one result. A tight contact gave a barely sensible current; a loose contact gave a current which could be maintained permanently equal to that which would be produced through a similar resistance by the eighth or tenth part of a Daniell's coii, --a strength sufficient to signal through a cable to America, if ever one be laid. I next tri...

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Product Details

General

Imprint

Rarebooksclub.com

Country of origin

United States

Release date

March 2012

Availability

Supplier out of stock. If you add this item to your wish list we will let you know when it becomes available.

First published

March 2012

Authors

Dimensions

246 x 189 x 22mm (L x W x T)

Format

Paperback - Trade

Pages

426

ISBN-13

978-1-130-92745-0

Barcode

9781130927450

Categories

LSN

1-130-92745-8



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