596 SEC. 14. METEOROLOGY. 



The clock, which goes 8 days, indicates the minutes only, and shifts" the 

 paper by causing the large cylinder to rotate 2 inches of its circumference 

 exactly at the hour, thus removing the portion of paper (2| inches long) 

 exposed during the past hour, and exposing a fresh portion, to be in its turn 

 removed at the end of another hour and succeeded by a new piece, and so on. 

 At the end of 24 hours the whole strip of test-paper is unrolled by the ob- 

 server from the large cylinder, dipped, and read by the scale (Schonbein's) ; 

 a fresh strip is then rolled round the small cylinder, and its free end is 

 attached to the large cylinder as before. 



The instrument was made for me by Mr. Casella, in 1868, after a plan of 

 my own suggestion. 



Most of this description is taken from a letter to Mr. Glaisher, published 

 in the " Proceedings of the Meteorological Society," Vol. IV., p. 326. The 

 results of some observations made with the instrument will be found in the 

 " Proceedings of the Meteorological Society," Vol. V., p. 51. 



2906. Aspirator, with gutta percha tubing and wooden box 

 for tests, used by the Ozone Committee during their experiments 

 in 1869. Scottish Meteorological Society. 



The small tin box was made by a native Arab for Dr. Arthur Mitchell, in 

 connexion with ozone experiments made by him in Algiers in 1855. 



2907. First Ozone Generator. Dr. Werner Siemens. 



The air or oxygen to be ozonised is caused to pass between two concentric 

 cylinders coated with tinfoil, and electrified by an induction apparatus. 



2907a. Tisley's Ozone Generator. The central tube being 

 used as a water channel, a uniform low temperature can be main- 

 tained, thereby greatly improving the per-centage of ozone. 



Tisley and Spiller. 



X. MISCELLANEOUS. 



2909. Plan and View of the Observatory of the Imperial 

 Central Institute for Meteorology and Terrestrial Magnetism, 

 Vienna. 



I. R. Central Institute for Meteorology and Terrestrial 

 Magnetism, Vienna. 



The building was erected, under the direction of the Imperial Minister of 

 Education, by the architect Ferstel, and finished in April 1872. The Obser- 

 vatory is provided with a great number of self-registering instruments for all 

 observations, among which may be particularly noticed Dr. TheorelFs printing 

 meteorograph for meteorological observations, and Adie's photograph ical 

 magnetometer (Kew model), for the observation of magnetic variations. 



2910. Meteorological Photographs, specimens as ordi- 

 narily produced at the Radcliffe Observatory, Oxford, containing 

 the unreduced observations made with the barograph, thermo- 

 graph, hygrograph, and anemograph, by the use of the waxed 

 paper process, from November 19th to December 6th, 1873. 



Rev. Robert Main, Oxford. 



