the mirror type is that a much longer scale is possible than with instruments furnished with a pointer, and hence greater accuracy in determining temperature readings may be secured. [Illustration: FIG. 11.—LAMBERT’S ANTI-VIBRATION STAND FOR GALVANOMETERS.] [Illustration: FIG. 12.—SIEMENS’ THERMO-ELECTRIC INDICATOR.] In suspended coil instruments furnished with a pointer, the construction differs only in detail from the foregoing. In place of the mirror, a light pointer is attached to the suspension so as to rest on the coil and a scale is furnished over which the pointer moves. Fig. 12 is an example of this type, made by Messrs Siemens, the suspension being contained in the tube which rises from the body of the instrument. The maximum length of scale moved over by the extremity of the pointer is about 6 inches, as a longer and therefore heavier pointer would reduce the sensitiveness below the point requisite for thermo-electric work. In the double-pivoted type, the suspension is eliminated, and pivots are fastened to each end of the moving coil which rest in bearings. The turning of the coil is made to compress a hair spring, made of phosphor-bronze; and when the current ceases the unwinding of this spring restores the coil to its former position. The coil carries a pointer which moves over a scale. These instruments are not so sensitive as those in which the coil is suspended, but can be made sufficiently sensitive to work with any kind of junction in practical use. The pivoted form is cheaper and stronger than the suspended type, and is used whenever sufficiently sensitive. The “Uni-pivot” galvanometer, made by R. W. Paul, is shown in figs. 13 and 17. The coil, which carries the pointer, is circular, and moves round a spherical core of iron placed between the poles of the magnet. A hole is drilled in the iron core, and the coil rests on a single bearing at the bottom of this hole. A phosphor-bronze control-spring serves to restore the coil to the zero position. The lessened friction due to the use of a single pivot enables this instrument to be made very sensitive when needed, so that a relatively small rise in the temperature of a junction may cause the pointer to traverse the whole length of the scale. [Illustration: FIG. 13.—PRINCIPLE OF UNI-PIVOT GALVANOMETER.]