| Description | Birt discusses his plan regarding the observations of the electrometers with a vein to the deduction of the laws of the diurnal or other periodical changes.
Birt discusses what the observations consist of. Discussion on what the different tables for each year will consist of. The days in which N electricity has been indicated by the instruments to ascertain P electricity for each of the remaining days will form the first table. Table II will show the amount of N electricity and the circumstances in which it was exhibited. Table III using table I will show the daily amount of P electricity on the days it was higher or lower. Table IV will give the absolute highest or lowest reading. Table V will give the mean of all the positive readings at each of the four periods of the observation. Table VI will refer to the mean electrical tension. Table VII will use table VI to show the maximum and minimum amount during the diurnal period. Table VIII using table V will give the diurnal electrical tension in quarterly periods.
Discussion on the mean curve of each year and mean curve from all observations. The numbers in table V will be projected in 12 curves to show the diurnal variations of the electrical tension. The numbers in table VIII will be projected in four curves.
Discussion on the days of periodical variation, of evident disturbance and diurnal variation.
Birt discusses the affections of the electrical apparatus at Kew. Reference to Mr [Francis] Ronalds experiments regarding the electrical insulation at different heights of atmospheric conductors. Discussion on collecting electricity from the atmosphere. Comparisons between the electrometers at Kew Observatory and Royal Observatory, Greenwich.
Birt compares the instruments and Kew with Greenwich such as the principal conductor, and their position. Discussion on the accuracy of results, and using the thermometer attached to the barometer. |