

BAIRD &TATLOCK. (LONDON) LTD. 



4758 



'. 



4749.4757 







4760 



per ft. 

 One end of tube is closed by a 





 

 

 



Sulphur Apparatus generally adopted by gas examiners for testing the purity of 

 coal gas. 



4749 Bunsen burner, steatite top, metal stand, with air-holes and depression for wide end of 



trumpet tube . . . . ..012 



4750 Trumpet tube .... . . . . 



4751 Glass cylinder with hole in bottom . . . . . . . . . . . . . . 



4752 Glass marbles for cylinder . . . . . . . . . . . . per 100 



4753 Beaker . . . . . . . . . . . . . . ..00 



4754 Condenser tube, bent 



4755 Wooden table support, adjustable 



4756 Indiarubber cap 



4757 s Indiarubber tube to suit above, i in. bore 



4758 Ammonia Cylinder, glass tube, filled with glass beads. 



stopcock, and the other by a tube ground to fit . . . . . . . . 09 



4759 Wooden Stand for same . . . . . . . . . . . . ..04 



4760 s Farmer's Gas -Calculator. A graphic method for the correction of gas-volumes, 

 especially for nitrogen-determinations. For the use of teachers, students, and all chemical 

 works in which gas analysis or nitrogen-determinations are required. By R. C. Farmer, 

 D.Sc., Ph.D. Published" by Baird & Tatlock (London) Ltd. . . ..03 



Much time is lost in the re-calculation of gas volumes to normal temperature and pressure ; and even when 

 tables of corrections are used, interpolations are generally necessary. 



By the use of this graphic method the corrected volume of I cubic centimetre of gas, either wet or dry, can 

 be found with an accuracy of about 2 parts in 10,000 in one single operation, thus eliminating all errors and 

 effecting a great saving of time in all work on gases. 



A cursor is laid across the diagram joining the points indicating the temperature and pressure at which the 

 gas was measured, and the corrected volume is read off directly. Conversely, the temperature or pressure can 

 be found if the volume is known. The logarithm of the corrected weight of nitrogen can be read off at the same 

 time, thus reducing the calculation of nitrogen percentages to a very simple operation. 



A series of tables relating to gasometric work and a set of logarithms are attached to the diagram in a con- 

 venient form for reference in conjunction with the calculator. 



CROSS STREET HATTOKT GARDE1ST, E-C 



864 



