It is even somewhat precipitate to assume that a mean value deduced from a single year is fairly representative of average conditions.
In practice it is found desirable that the mean value of the obliquity of action during the contact of teeth should not exceed 15, nor the maximum value 30.
In all cases the mean value for the 24 hours is taken as 100.
In spite of this difficulty, however, the values of the correlation coefficients so far obtained cluster fairly well round the mean value of all of them, which is almost exactly 2.
Soc., 1899, 55, p. 213), the mean value obtained being 52.06; and also by C. Meinecke, who estimated the amount of silver, chromium and oxygen in silver chromate, the amount of oxygen in potassium bichromate, and the amount of oxygen and chromium in ammonium bichromate (Ann., 1891, 261, p. 339), the mean value obtained being 51 99.
His mean value for November and December was 129, while his mean for May and June was only 47.
In reality the December range was 82, the June only 57 volts; but the mean value of the potential was 243 in December as against III in June.
The same observer from four weeks' observations at Hammerfest got the considerably lower mean value 58, with a maximum of 252.
In this table, unlike Table IV., amplitudes are all expressed as decimals of the mean value of the potential gradient for the corresponding season.
Liideling (9) found for the mean value for 1904 in volts per metre 242.