' 



BAIRD ^T^TLOCK (LONDON) LTD. 



4801 

 Laboratory Governors. 



4803 



4805 



For governing the flow of gas and rendering it independent of fluctuations of pressure, the most accurate 

 instrument is the Balance Governor, so called because a bell carrying the valve is balanced in a tank of water 

 or the like. For many purposes a slightly less sensitive form is sufficient and this is furnished by our Double-Dry 

 (leather diaphragm) governor. It is often required, however, to decrease the pressure by a few inches before 

 the gas passes to the measuring apparatus and to the balance governor for final adjustment. For this purpose 

 we make a dry (leather diaphragm) or wet (floating bell) Service Governor. Particulars of all these forms will 

 be found below. 



480 1 T Balance Governor, very delicate. Tank and bell in incorrodible porcelain, being imper- 

 vious to foul gas and always equal in appearance to new. Long stroke valve. Beam of 

 japanned brass on pillar with anti-friction wheels. Counterbalance consisting of tube for 

 shot and sliding weight on beam. The most sensitive governor manufactured. Complete 

 with syphon cocks, the whole being mounted on small table 



4 10 



4802 T Balance Governor, exactly as above, but tank and bell in japanned tinned steel, complete 400 



4803 T Balance Governor, simple form, but equally sensitive to above, with beam balanced on 

 knife edge, with counterbalanced shot tube, inlet union, and outlet tap and connection. 

 A very sensitive, reliable and cheap instrument 



4804 T Double-Dry Governor, consisting of two diaphragm governors, the leather being specially 

 selected and prepared. With brass pressure weights, and cup for fine adjustment. In 

 japanned box with inlet and outlet connections 



4805 T Service Governor, consisting of suspended valve with leather diaphragm and spring 

 adjustment. In cast-iron with cover, 3-light size without base, IS/- ; on base 



Photometer Benches. 



The particulars of photometers which we are prepared to supply are divided into three types. 



A. High Class Laboratory Benches, with steel tubes, following the model used at the National Physical 



Laboratory. 



B. Well-made Technical Benches with Wooden Bars of standard section. 



C. Portable Photometers. 



In Class A the price in each case includes three carriers, i.e. one for the standard of light, one for the photometer 

 head, and one for the light under test. 



Otherwise the prices of carriers, standard of lights, photometer heads, lamp rotators, etc., are given separately, 

 but one or two complete equipments are priced as complete photometer sets. 



2 10 



100 



19 



(CHEMICAL AND SCIENTIFIC APPARATUS AND PURE CHEMICALS- 



875 



