568 SEC. 14. METEOROLOGY. 



II. BAROMETERS. 

 a. MERCURIAL. 



2790. Large Standard Barometer, ^ tube, with English 

 an<J metrical scales, glass plunger cistern, and pipette in tube for 

 preservation of vacuum. Patrick Adie. 



2791. Medium Standard Barometer, ^ tube, with glass 

 plunger cistern, and pipette in tube for preservation of vacuum. 

 As used in Government meteorological observations. 



Patrick Adie. 



2792. Small Standard Barometer, with glass plunger 

 cistern, and pipette in tube for preservation of vacuum. Medical 

 Department, War Office pattern. Patrick Adie. 



2793. Large Standard Barometer, with English and 

 metrical scales, single readings, Kew Observatory verification, 

 and pipette in tube for preservation of vacuum. Kew pattern. 



Patrick Adie. 



2794. Medium Standard Barometer, with English and 

 metrical scales, single readings, Kew Observatory verification, and 

 pipette in tube for preservation of vacuum. Kew pattern. 



Patrick Adie. 



2795. Mountain Barometer, Fortin's, on tripod, with pipette 

 in tube for preservation of vacuum. Patrick Adie. 



2796. Gay-Lussac's Portable Barometer, with pipette in 

 tube for preservation of vacuum. Patrick Adie. 



2797. Mercurial Barometer, an old Dutch instrument by 

 Reballio, combining syphon and long range barometer, thermo- 

 meter, and hygrometer. M. Pillischer. 



2798. Drawing of a " Balance " Barometer, of which a 

 model was executed, submitted to the Royal Irish Academy, and 

 tested during some months. Jos. P. O'Reilly, Dublin. 



The column is inclined from the vertical, and suspended by a knife edge, as 

 the beam of a balance, whence the proposed name. The displacement of the 

 mercury in the column causes this to incline more or less from the vertical, 

 the amplitude of movement showing itself on a graduated limb by means of 

 an index. The mode of action and the degree of sensitiveness of the instru- 

 ment are therefore comparable to those of a beam balance, and the indications 

 given without the intervention of wheel work. 



2799. Barometer of De Luc, formerly belonging to H. B. 

 de Saussure, and carried with him in his Alpine excursions. 



H. de Saussure, Geneva. 



