Natural philosophy for general readers and young persons / translated and edited from Ganot's Cours élémentaire de physique (with the author's sanction) by E. Atkinson.

  • Atkinson, E. (Edmund), 1804-1887.
Date:
1878
Catalogue details

Licence: Public Domain Mark

Credit: Natural philosophy for general readers and young persons / translated and edited from Ganot's Cours élémentaire de physique (with the author's sanction) by E. Atkinson. Source: Wellcome Collection.

    570/618 (page 548)
    tremities of a galvanometer wire, when the thermoelectric current is to be observed. A Nobili's pile in combination with a galvanometer constitutes the most delicate and accurate means of measuring temperatures. Such an arrangement was first used by Melloni in his researches on the transmission of radiant heat. The arrangement he used is represented in fig. 454. On a wooden base, provided with levelling screws, a graduated brass rule, about a yard long, is fixed edgeways. On this rule the various parts composing the apparatus are placed, and their dis- tances can be fixed by means of binding screws. <z is a support for i^'ig. 454- a Locatelli's lamp, or other source of heat ; F and E are screens ; C is a support for the bodies experimented on, and m is a thermo- electrical battery. Near the apparatus is a galvanometer, D, which has only a comparatively few turns of a tolerably thick (i mm.) copper wire. Such galvanometers are called thcrmoimiliipitcrs (479\ The delicacy of this apparatus is so great that the heat ot the hand is enough, at the distance of a yard from the pUe, to deflect the needle of the galvanometer.