cr 



BAIRD &TATLOCK (LONDON) LTD, 



Sr, 





SECTION No. 6. 



Chemical and General Apparatus. 



1900 1901 1902 1903 



1900 Adapters, small, for Liebig's condensers, straight or bent 



1901 Adapters, bent form, of heavy Bohemian glass. 



Length . . . . . . 8 by ij 10 by 



1903A 

 each 004 



Each 



6d. 



1902 Adapters, straight form, of heavy Bohemian glass. 

 Length . . . . . . 10 by i 



Each 8d. 



9d. 



12 by i 

 9d. 



12 by 2 in. 

 I/- 



14 by 2 in. 

 lOd. 



1903 s Anemometer, Fletcher's, for measuring speed of flue gases. Price, in polished mahogany 

 case 



This is a convenient apparatus for measuring the speed of draught in the flues of chemical works, where any 

 fine mechanism would soon be ruined. It is based upon the movement of a column of ether in a U tube (described 

 in " Lunge's Sulphuric Acid and Alkali," 1,330 ; in, 361). Illustration shows this in the simpler form, leaving out 

 the microscopes, which are quite unnecessary for reading the divisions of the scale or vernier. The ends of the 

 glass tubes, (a 6), should be placed rather less than one-sixth of the diameter of the flue from its inner wall. The 

 straight end of (a) ought to be as exactly parallel as possible to the direction of the draughts ; the end of (fr) ought 

 to be exactly at a right angle to this, and so that the current would blow right into it. Without this precaution 

 a mistake is made, which is avoided by the arrangement shown in Fig. igo3A, and proposed by Hurter, viz., employ- 

 ing tubes with ends bent in opposite directions. The tubes (a b) communicate with the ether tube (cd>, , the draught 

 causes the ether to rise in (a) by aspiration, to fall in (6) by the pressure of the air blowing into the tube. The 

 difference of level between (c) and (d) is read off by means of the scale and vernier. When the sliding disc () is 

 turned 180, the currents are reversed. There will now be a difference of levels in the opposite direction, but 

 equal in amount to the first, if the observation is correct. The sum of these two differences is meant by the 

 " Anemometer Readings " in the tables. 



(See " Alkali Makers' Handbook," Lunge and Hurter, p. 87.) 



3 10 



1904 



1904 U Anemometer, inclined pattern, with levelling screws to stand, sliding verniers, and scale 

 complete in portable case 



330 



ICHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS. 



383 



