III—On the Number of Dust Particles in the Atmosphere of certain Places in Great Britain and on the Continent, with Remarks on the Relation between the Amount of Dust and Meteorological Phenomena

Extract

In a new investigation of this kind it is always desirable to repeat the observations under as many conditions as possible. The variables are so many that with a limited experience it cannot be expected that the subject will be exhausted, or that the conclusions arrived at from early observations will be in all cases confirmed. As an opportunity offered in the beginning of 1890 for repeating the tests made the previous year on the amount of atmospheric dust at different places on the Continent, it seemed desirable that the old ground should be gone over again rather than that the investigation should be extended to new areas. The observations made in this country have also been confined to the same stations as in 1889; and in this paper I intend giving the results of a series of tests repeated at the same stations, at about the same dates, but under the conditions existing in 1890, as has already been given for 1889 in Part I. of this subject.