SECTIONAL TRANSACTIONS.—A. 427 
Of ninety-eight days of observation at Stonyhurst in the five months, January 
to May, 70 per cent. have been spotless. The mean area, too, of such spots 
as have been observed has been very small, not more than 32 millionths of the 
visible disc. The facule, though extensive, have been very faint. The 
minimum of solar activity in the cycle has almost been reached. 
(3) But one small spot in latitude —6° and longitude 3.2°, observed 1923, 
April 19-29, is connected with the recent series of magnetic disturbances, and 
the faint facule observed have clustered about the same mean position. More- 
over, this spot and the facule mark a patch or region of the sun’s surface 
which has been intermittently disturbed since 1923, November. Similarly, the 
recent series of magnetic disturbances of 1923 is a continuation at each synodical 
solar rotation, with one period of magnetic calm excepted, of a long series 
beginning 1921, October 27, and extending altogether over 594 days. 
(4) The mean synodical interval of this long series is exactly twenty-seven 
days. This corresponds to a mean daily rotation in are on the sun’s surface 
of 14.32°, which is the rotation period, adopting a mean value from Carrington’s 
and Spoerer’s formula, for latitude +8.7°. The mean value of the longitude of 
the sun’s central meridian for all the days of this long magnetic series was 
336.6°. The mean value of the latitude of the intermittent solar disturbance 
was —6.1°, and of the longitude 343.5°. There is, therefore, complete accord 
between the series of solar disturbances and the series of magnetic disturbances. 
Consequently, a definite region of the sun can affect the earth magnetically 
even when there are no visible disturbances upon it. 
12. Mr. W. M. Morpey.—Lecture on Some Recent Studies im 
Alternating Magnetism. (Illustrated by Experiments and 
Lantern Slides.) 
The following experiments, amongst others, were shown and described :— 
(1) Repulsion from an alternate current multiphase magnetic field, of iron 
magnetite and other magnetic substances placed at a distance of several inches 
from the poles. 
Attraction of these substances to the magnet when the distance is small. 
(2) Steady movement or migration of these substances through the magnetic 
field, and repulsion from that field. 
(3) Repulsion from a 1-phase magnet of specular hematite which forms a 
halo round and at a considerable distance from the poles. 
Absence of lines of force in the halo. 
(4) Illustration of lines of force in alternating fields of various substances, 
including Heusler alloys. 
(5) Water containing certain magnetic materials driven uphill and discharged 
from a multiphase field—a surface tension effect. 
) Separation of certain mineral substances from their gangue in multiphase 
fields. 
(7) No movement of finely divided aluminium in these alternating fields, 
indicating that the above effects are not due to eddy currents, and that they are 
due to or associated with hysteresis. 
f2. Mr..S. G. Brown, F.R.S.—Demonstration of the ‘ Freno- 
phone,’ or Friction Operated Loud-Speaker. 
Apparatus in which very high magnification of the received signals or 
speech is obtained by means of the friction existing between a polished glass 
dise and a small cork pad rubbing upon its surface. The disc is rotated by 
clockwerk. The received telephonic current is applied to the coils of a receiver 
of the reed type; the reed presses upon the pad, which in turn bears upon the 
disc. The vibratory pressure of the pad causes large vibratory changes in the 
frictional drag imparted to the pad; and by linking the pad to a telephone 
diaphragm, so that it is caused to vibrate as the result of the tangential vibra- 
tions due to the drag of the disc upon the pad, very loud speech, &e., is set 
up in the sound-emitting trumpet. 
