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not in use. The earth connection is then broken, and the can 
is drawn down about eighteen inches. Immediately the 
electrometer shows a large effect (from five to fifteen degrees 
on my divided ring electrometer, in the state it chanced to be 
in, requiring more than one hundred degrees of torsion to 
bring it back to zero, in the few observations I made). When 
the surface of the earth is, as usual when the sky is cloudless, 
negative, the electrometer shows positive electricity. But 
when a negative cloud (natural, or of smoke) passes over, the 
indication is negative. The insulation is so good that the 
changes may be observed for a quarter of an hour or more, 
and when the can is put up the electrometer comes sensibly to 
zero again, showing scarcely any sensible change when the 
earth connection is made, before making a new start.” 
Dr. Joule stated that he had recently witnessed experi- 
ments with Professor Thomson’s new Atmospheric Electro- 
meter, the merit of which consisted in its extreme sensitiveness, 
and the facility with which accurate observations could be 
made with it. 
A Paper was read by Mr. Richard Roberts, M. Inst. 
C.E., entitled, “Proposed Improvements in Pharology.” 
After adverting to the remarkable fact that the great 
majority of wrecks and collisions occurred in the immediate 
vicinity of the beacons intended to guard against them, Mr. 
Roberts mentioned that amongst the numerous schemes 
propounded for the improvement of our present system of 
pharology, that of Mr. Herbert, of the Admiralty, who pro- 
posed to moor a series of floating lighthouses of great power 
of illumination, in a direct line up the centre of the English 
and other channels, appeared the most worthy of attention. 
He (Mr. Robei'ts) perfectly agreed with this suggestion, to 
which his attention had been first called by Mr. Murphy’s 
paper, read in section G of the British Association, recently 
held at Leeds, when it at once occurred to him that the 
