154 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Wild lias published a short paper in the Bulletin of the 



Academy of St. Petersburg on Control Barometers that is 

 to say, such as are to be used in comparing station-barome- 

 ters with the standard one at the Central Station. He states 

 that his first experiments in this line were made with a new 

 siphon-barometer, constructed, according to his directions, 

 by Turretini, of Geneva. Several improvements have been 

 suggested in the course of his work; and two instruments 

 were constructed, with slight changes, by Brauer, of St. Pe- 

 tersburg, and C. H. F. Geissler, of Berlin ; and, lastly, one by 

 R. Fuess, of Berlin all three of which, he states, have given 

 such eminent satisfaction that we are finally in possession of 

 a thoroughly reliable and invariable portable mercurial ba- 

 rometer one whose indications may be relied upon to the 

 twentieth part of a millimeter or the five-hundredth part of 

 an inch. 



In a memoir upon Atmospheric Pressure, Pagona gives some 

 important measures of the corrections due to capillarity and 

 of the meniscus form of the top of the mercurial column. 

 In a siphon barometer the height of the meniscus in the two 

 legs is seldom the same. In comparing any barometer with 

 a standard, he finds the relation of the former to the latter to 

 vary with the pressure, temperature, and diameter of the tubes. 



Goldschmid invented before his death a very delicate self- 

 recording attachment to his form of aneroid barometer. A 

 test series of observations at Zurich shows that his apparatus 

 gives quite as good results as ordinary readings. 



The Goldschmid aneroid, whose introduction during the 

 past ten years has extended throughout Germany and Switz- 

 erland, has been materially improved upon by Professor A. 

 Weilenmann, of Zurich. These improvements were proposed 

 by him in 1872, and in the twentieth volume of the Quarter- 

 ly of the Zurich Association he gives the results of an ex- 

 tended study of the merits of his improved aneroid. The 

 analytical investigation of the errors to which the aneroid is, 

 in general, subject, is, we believe, fuller than any hitherto 

 o;iven ; and the formula 1 thence deduced for his own instru- 

 inent show that, after determining the four instrumental con- 

 stants or the corrections for temperature, pressure, errors of 

 scale divisions and micrometer screw, and gravity his in- 

 strument during a year, and for a range of 60 temperature 



