the redundant fluid in the globe had been so much as of that in the hemispheres, I must have perceived it. As it might be suspected that in the principal experiment the neighbourhood of the hemispheres communicating with [the] ground would enable the globe to hold more than it would otherwise do, and that therefore the cork balls would not separate so much as they would do if the hemispheres were taken away and the quantity of redundant fluid in the globe was the same, and consequently that the above computation of the quantity I could perceive is not just, I took away the hemispheres, made the corks touch the globe, and electrified it till they separated, then holding the hemispheres in my hands as near the globe as in the experiment, I did not perceive any alteration in the separation of the corks. The outside diameter of the hemispheres was 13.3 inches. 563] Experiment to see whether the force with which two bodies repel is as the square of the redundant fluid in them*: tried with straw electrometer and glass globes. The two electrometers were hung at opposite ends of a horizontal stick of wood 43 inches long, supported on sticks of waxed glass and communicating near the middle with one of the globest. The same string also which lifted up the electrifying wire let down a piece of wood for making a communication between the two globes. The board with divisions was placed 6 inches behind the electrometers, and the guide for the eye 30 inches before it. The electricity of the globes wasted very slowly, so that it could not be sensibly diminished in the time between reading off divisions to heavy electrometer and those to light one. The electrifying wire rested on horizontal wood while globet was turned, two jars being used as a magazine to prevent the globe Leyden vial from charging too fast. The globe was turned till the heavy electrometer separated to rather more than the intended division, after which I waited till it came right, when by the string I lifted up the electrifying wire and made the communication between the two globes and looked at the division of light electrometer. The electricity of the magazine was discharged as soon as the electrifying wire was lifted up. 564] One of the straws used for the heavy electrometer was black in some places, and is called "blighted," the other is called "fair." [See Art. 386.] + [The coated globes 2 and 3. Their charges are given in Art. 505 as 1782 and 1555 circ. inc., or 1159 and 1009 glob. inc., the sum of which, 2168, agrees with Art. 391.] [Of Nairne's electrical machine.] The additional wire was run into straw very easily, and was fastened by putting a little wax on the end, which by heat was pressed quite smooth against the end of the straw. Mon. morn. Jan. 25. Th. 55. N. 20. The globe 3 was made to communicate with horizontal wood, then if 8 heavy electrometer separated to 9 divisions, the light electrometer 10 separated, on communicating electricity to globe 2, to the same number of divisions. 565] Trials of time in which the electricity of jar 1 was diminished by these straws from degree in which the heavy electrometer used in former experiments of this kind to that in which the pith balls began to close. After standing In the afternoon the blighted straw was by mistake for the other covered for an hour with paper soaked in salt water. about an hour to dry, it was found that when heavy electrometer was made to separate 10 divisions, light separated 11. The blighted 5′′ 22' straw discharged the electricity as before in weight of blighted straw 17.8. The fair straw was then kept in salted paper in the same manner for about 3 hours. Tu. morning. Th. 57. N. 23. If heavy electrometer separates to 15, 10, 9, 8, light electrometer separates about less. Fair straw discharged the electricity almost immediately, blighted in about 5". When fair straw rested on cork ball it was about 30", the blighted was much longer. The blighted straw was kept in salted paper for 1 hours, and then set to dry till the afternoon. In the afternoon its ball was moistened with salt water. Fair 2" 2" straw closed in about when resting on straw, and about 5" or 7" when resting on cork ball. In about 1 hours after they were tried again without any alteration having been made. The light straw N° 1 was soaked in salt paper at night for 3 hours. Wed. Jan. 27. Th. 57. N. 23. When heavy sep. to 15, light at 14, but increased after a time to near 15. As it was suspected that this increase might be owing to the air being electrified, I tried and found the air to be much electrified in all parts of the room. The ball of N° 1 was then moistened with salt water. Heavy sep. to 15, light to 13, but increased to near 14. In order to avoid in some measure the inconvenience from electrifying the air, Richard turned the globe, by which means the electricity was not made so strong. N° 1 closed in about 4" whether resting on ball or straw. N° 2 was soaked in salt water for 24 hours till 3 in afternoon, about 5 or 6 it was tried. 15 15 heavy to light to 1st time, for several times after to 14. 91 As it was found the preceding day that the straws conducted ill, they were kept ab ut 3 or 4 hours in the morning in salted paper, at about 3 they were taken out of the paper and hung up to dry. In the afternoon they were tried, a screen being placed to keep them from the fire. 566] After the additional wire had been taken from the heavy electrometer, the two electrometers were electrified and compared to gether without the process of communicating the electricity from one globe to the other, when they stood as follows. If globe 2 was electrified till D° electrometer separated to 17, on communicating electricity to globe 3 it separated to 91. 17 The light straw electrometer was then placed instead of the paper electrometer, and a paper with divisions placed behind it. It was found that when heavy straw electrometer separated to divisions, the light straw electrometer separated to 91 567] As the straws seemed not to conduct well enough, they were gilt. The gilding was not perfect in several places, but it was sufficient to conduct the shock of a jar very weakly electrified. The globe 2 electrified and communicated to globe 3. It was found that some electricity ran from the electrifying wire to the knob of the globe to which electricity was to be communicated, on |