The chief errors to which the stereometer is liable are (I) variation of temperature and atmospheric pressure during the experiment, and (2) the presence of moisture which disturbs Boyle's law.
In most cases the figures are based on the number of days of thunder at a particular station, or at the average station of a country; but the second set Table Annual Variation of Thunderstorms. average annual number of thunderstorm days to be respectively 6.4 and Io.
This work, which embodied the results of many years' research, was distinguished by its strict adherence to the scientific method of investigation by experiment, and by the originality of its matter, containing, as it does, an account of the author's experiments on magnets and magnetical bodies and on electrical attractions, and also his great conception that the earth is nothing but a large magnet, and that it is this which explains, not only the direction of the magnetic needle north and south, but also the variation and dipping or inclination of the needle.
The implication of the phrase may go farther, suggesting that there is no connexion between the appearance of the variation and the use to which it may be put.
Lutheran influence can likewise be traced in way of variation introduced into the baptismal and other sacramental or occasional offices.
Darwin was well aware that variation ranged from differences so minute as to become apparent only on careful measurement to those large departures from the normal which may be called abnormalities, malformations or monstrosities.
They can adapt their motions to every variation of the ground over which they move, yet all varieties of snake locomotion are founded on the following simple process.
Amid all the variation in their details, and the apparent confusion introduced by Napoleon's habit of suggesting alternatives and discussing probabilities, and in spite of the preparations ostensibly made for an expedition to Ireland, which was to have sailed from Brest and to have carried 30,000 troops commanded by Augereau, the real purpose of Napoleon was neither altered nor concealed.
Deals with the variation of thunder over longer periods.
In the second place, it has been urged, particularly by de Vries, that experiment and observation have shown that the possible range of fluctuating variation is strictly limited.