1866. | Physical Science. 527 
Tn one instance the appearance of a meteor in the spectroscope was 
unaltered, being that of an ordinary yellow shooting-star, leaving a 
yellow streak upon its course; and when the spectrum of the 
meteoric streak was diffused, a bright yellow very slender line 
was frequently observed in the spectrum on the side towards the 
red. The presence of the bright yellow line in a very conspicuous 
form in many of the streaks, points to the conclusion that sodium is 
frequently present. 
Mr. Birt then read the report of the lunar committee for 
mapping the surface of the moon, from which it appeared that maps 
had been drawn on a scale of 100 inches for the diameter of the 
moon, some part of which had been enlarged to 400 inches, and 
a number of observations catalogued, which exceeded anything 
previously attempted. Mr. Browning gave a description of some 
recent improvements in astronomical telescopes with silvered glass 
specula, in which he described an improved method of mounting 
the speculum. 
After a paper by Dr. Gladstone and Rev. T. P. Dale on 
dispersion equivalents, Mr. J. P. Harrison read a paper on the 
heat attained by the moon under solar radiation, from which it 
would appear that on the 22nd day of lunation, seven days after 
full moon, the temperature of the moon would be 840° F., a 
temperature of about dull redness, and exceeding the fusing point 
of tin and lead. 
Amongst the papers read the next day was one by Mr. Hooper, 
on the electrical and mechanical properties of Hooper’s India- 
rubber for submarine cables. He reduces the general coatings of 
India-rubber by means of heat to one perfectly homogeneous 
coating, separated by a film of vulcanized India-rubber, the 
advantages claimed are durability and resistance to mechanical 
injury, permanency of insulation at high temperatures, imperme- 
ability under long immersion and pressure in water, freedom from 
defects in manufacture, and high state of insulation with diminished 
induction. One hundred and fifty miles of this wire have been sent 
to India, and the insulation per nautical mile is about forty times 
better than that of the Persian Gulf core. 
Professor Jellett then gave a paper on a fluid possessing the 
power of rotating the planes of polarization of rays, of the opposite 
ends of the spectrum in opposite directions; and Mr. Hind after- 
wards made some remarks on the recent extraordinary outburst of 
the variable star in Corona, from which it would appear that the 
change in the star did not take place with such astonishing 
suddenness as had been generally assumed. If such were the case, 
it destroyed the romance of its bemg a world in conflagration. 
