

BAIRD &TATLOCK (LONDON) LTD. 



The oil-cup is filled with the cooled oil, so that the gauge-point is covered, and the apparatus is then trans- 

 ferred to an efficient ice-chest of suitable design and the instrument levelled by means of the tripod-screws and 

 spirit-level provided for that purpose. 



As it may be necessary to make more than one test, it will be found desirable to have at least half a pint 

 of the oil in a stoppered glass bottle placed in the ice-chest with the instrument until required for use. 



Before commencing a test, the level of the oil in the oil-cup is brought exactly to the point of the gauge. A 

 narrow-necked flask, of 50 cubic centimetres capacity to a mark on the neck, is placed beneath the jet and the 

 ball valve raised and suspended from the thermometer-clip by means of the hook on the stem of the valve, a stop 

 watch being started simultaneously with the lifting of the valve. During the period of testing, the temperature 

 of the oil must remain constant at 32 F. The time of outflow for 50 cc. is noted, and the result given in seconds. 



If the oil-cup requires to be wiped out, tissue paper rather than cloth should be employed, as filaments of the 

 latter may be left adhering to the surface of the vessel. The agate orifice must not be cleaned with anything 

 which is likely to cause abrasion, and it has been found best to employ twisted tissue paper for the purpose. 





5008 



5008 T Ice Chamber, for use with Sir Boverton Redwood's Viscometer (Admiralty pattern), 

 to enable tests to be made at 32 F. The chamber is made of zinc, well insulated and 

 fitted in oak frame, with glass panelled door, size of inner chamber 24 x 14 X 14 in. . . 12 



10 



CROSS STREET HATTOTST GARDEN, E-C 



