448 Scientific Proceedings, Royal Dublin Society. 
Three photographic cameras were employed to take pictures of 
the corona; but none of them were provided with equatorial 
motion, having only a rough movement in zenith distance, and 
none in azimuth. The details are, therefore, to a great extent 
obliterated by the sun’s motion. An attempt was made to ob- 
tain photographic evidence of the polarisation of the corona by 
inserting a double-image prism between the lenses of a camera. 
The photographs obtained in this way were examined by Prof. 
Pickering, who found inequalities in them, which, as far as they 
go, tend to indicate tangential polarisation ; but in the opinion 
of Dr. Hastings the evidence is not conclusive. The inner corona 
was seen by Mr. Seagrave about 30° before totality. Mz. Pulsifer, 
using a ten-prism spectroscope attached to a four-inch Clark 
refractor, and keeping the slit tangential, observed the reversal 
of the Frauenhofer lines at the commencement of totality. From 
the length of these lines, which only reached one-third across the 
spectrum, the tangential thickness of the reversing layer was 
found, and from this Mr. Pulsifer infers its minimum height 
above the photosphere to be 524 miles. The C line was not 
shortened like the others, but extended right across the spec- 
trum. 
While many researches are continually being made in order to 
connect the sun-spot cycle of eleven years with various meteoro- 
logical phenomena, the old question whether solar activity is 
different in different heliocentric longitudes, has been revived. 
Dr. Gruss, of Vienna (A.N.), finds from observations of tempera- 
ture made at Prague during 1876, a period of 25°56 days, while 
observations of the direction of the wind gave 2671 days. It 
will, no doubt, always be extremely difficult, if not impossible, to 
arrive at a satisfactory result by examining observations made at 
one station only, where local circumstances may influence the 
result so considerably. 
Prof. Balfour Stewart and Mr. Dodgson have sent a preliminary 
report to the Royal Society (“ Proceedings,” xxix., p. 308), in 
which they investigate the diurnal ranges of temperature at 
Kew, Toronto, and Utrecht, and the diurnal ranges of magnetic 
declination at Kew and Prague. The results are, that the ranges 
of temperature exhibit certain common periods (around 24 days) ; 
that similar phases appear to occur at Toronto eight days before 
