The Bulletin. 



11 



A number of factors influence the determination of the flash- 

 point of an oil and cause it to vary according to the conditions under 

 which the test is made, e. g., the rate of heating, the size and depth 

 of the cup, the quantity of oil taken for the test, currents of air — 

 in fact, any cause producing the rapid evolution of a large amount 

 of vapor tends to lower the flash-point. Difl"erent types of instru- 

 mewts for taking the flash-point also give different results. This 

 fact is brought out in Table 1, which gives the flash-point of a 

 number of samples made with the Elliott Cup, the Open Tagliabue 

 Cup, and the Foster Cup. The results with the Elliott Cup are uni- 

 formly lower than the others. 



TABLE I. 



