Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1823 edition. Excerpt: ... DESCRIPTION A NEW MODE ELECTRICAL INSULATION, and of some EXPERIMENTS ON VESUVIUS, &c. Although atmospheric electricity, from the period of its first discovery, has always been esteemed an important subject of inquiry, and has been the object of much diligent and valuable investigation, it is regretted, that a register of careful observations upon it do not accompany those made in various places, on the pressure, temperature, humidity, &c. of the atmosphere. The difficulty, if not the impossibility of constructing a correct atmospherical electrometer, and the great inconvenience attendant on the use The electrometer here described differs very little from that which I hare described in the Quarterly Journal, vol. ii, p. 249, which is perhaps more convenient for portability. of the least objectionable kind of instrument (which, perhaps, is the "exploring wire" of Father Beccaria), are no doubt the causes of this omission. The known difficulty seems to be that of preserving the glass supports, or insulators of the wires or rods, in such a state, that, as far as they are concerned in insulating them, they may do so uniformly; but no attempts to effect this object have hitherto succeeded, probably because the deposition of moisture upon them, from the surrounding air, has not been totally prevented. Mr. Read imagined, that, if his insulators could be constantly kept in " due temperature," his rod would be always electrified; but he feared, that, as this could only be accomplished with the aid of common fire, it would be very difficult, in so large an apparatus, to apply neither too much nor too little. In the apparatus described below, the temperature of the insulator may be (constantly, or whenever an observation is made) raised a little...
