65 
was found to be in a perfect state after the ship had steamed 
100,000 miles. Dr. Joule drew attention to the great 
expansibility by heat of gutta percha even at a comparatively 
low temperature, and suggested that a series of alterations of 
temperature would produce a strain on that material when 
enclosed in an envelope of inferior expansibility as in the 
case of the Atlantic cable, which might occasion partial disin- 
tegration. 
Mr. Baxendale described the appearance of Donati’s comet 
seen through Mr. Worthington’s 13-inch reflecting telescope. 
He had not observed the spiral emanations from the nucleus 
noticed by Mr. Hind. There were several envelopes partly 
surrounding the nucleus. Latterly the nucleus had increased 
in brilliancy and become of a purer white. At the period of 
its greatest brilliancy the tail was 3G°long and 12° broad near 
its termination. The Chairiman and the Rev. H. H. Jones, 
both of whom had seen the comet of 1811, considered that 
of the present year far superior to it both as to size and 
brilliancy. Mr. Baxendale remarked that he had observed 
the comet recently discovered in Cambridge, U.S. It was 
in the constellation Aquarius, and visible, under favourable 
circumstances, to the naked eye. Mr. Jones believed that 
comets were for the most part strangers to our system, — 
but that wandering through space they might occasionally be 
drawn by the sun’s attraction and thus become members of 
the solar system for a time, or even in some cases permanently. 
He contended that the nebular hypothesis offered the best 
solution of astronomical phenomena. 
