TRANSACTIONS OF SECTION A. 405 
14. A Method of Increasing the Sensitiveness of cerlain Measuring 
Instruments. By G. A. SHakusprar, D.Sc. 
Any instrument the indication of which is made by the reflection of a beam 
of light from a mirror can be made more sensitive by allowing the mirror to 
reflect the image of a powerful source of radiation (e.y., a Nernst filament) on 
to the receiving vane of a radiomicrometer or other measurer of radiant energy. 
If the primary instrument be a galvanometer the movement of the image through 
1 mm. may produce a movement of the beam from the radiomicrometer through 
1,000 mm., thus increasing the movement observed 1,000 times. The beam from 
the secondary instrument may be allowed to fall on a tertiary one with a further 
magnification of a like order. In this way exceedingly minute rotations of the 
mirror of the primary instrument can be detected. The name ‘microtropo- 
meter’ is suggested for such a combination of instruments. 
WEDNESDAY, SEPTEMBER 17. 
The following Reports and Papers were read :— 
1. Report of the Seismological Commuittee.—See Reports, p. 45. 
2. Report on the Investigation of the Upper Atmosphere.—See 
Reports, p. 130. 
3. Report on the Further Tabulation of Bessel and other Functions.— 
See Reports, p. 87. 
4. Report of the Committee to aid in Hstablishing a Solar Physics 
Observulory tm Australia.—See Reporis, p. 132. 
5. Reporl of the Committee on Radiolelegraphic Invesligations.—See 
Reports, p. 131. 
6. Report of the Committee on Hlecirical Standards.—See Reports, 
p. 135. 
7. Report on the International Tables of Physical and Chemical 
Constants. 
8. A New Method of Sealing Electrical Conductors through Glass. 
By M. J. ANDERSON. 
While experimenting with a new method of starting mercury vapour 
apparatus? Mr. G. B. Burnside and the author experienced great difficulty at 
first in obtaining a satisfactory method of sealing the electrical conductors 
through the glass of the lamps with which the experiments were carried out. 
1 Proc. Roy. Soc. Hdin., xxxiii. (1913), p. 117. 
y ’ Pp 
