DFans: NE VS ACSA 140 Mar. 13 
neither this, nor any mechanical arrangement of flame, can overcome 
the difficulty of losing the l'ghter vapors in the open apparatus. 
We will now discuss the question of ‘closed testers.’”’ In these an 
effort has been made, with more or less success, to prevent the escape of 
the lighter vapors lost inthe open apparatus. Tagliabue, who made the 
first “‘open tester,’’ has also devised a closed apparatus. In this he 
has simply placed a heavy brass cover, with a system of valves and a 
little chimney for igniting the vapors in, upon his open tester. ‘The ap- 
paratus is not much better than an open tester, and has many draw- 
backs. First, it is extremely difficult to clean, since the valve-system 
below the cover dips into the oil, and it is impossible to clean the ap- 
paratus after using it with one sample of oil, and before using it with 
another. Secondly, the results obtained with this apparatus are but 
slightly lower than those obtained with a good open tester. In using 
the closed tester of Tagliabue it was noted that the enlargement of the 
flame took place at almost the same temperatures asin the open testers, 
the oil not flashing till many degrees above this point, a proof positive 
that this apparatus does not prevent the escape of the lighter vapors of 
kerosene. This last fact is partly due to the lack of space beneath the 
cover of the tester and the oil surface. 
Fully realizing the importance of this whole subject, the English 
government appointed a commission to report upon the question; and 
the result of this report was an apparatus devised by Prof. ABEL, the 
chemist to Woolwich Arsenal. Prof. ABEL insures the slow heating 
of the oil by using a large quantity of water and by using an in- 
termediate air-space between the water-bath and the _ oil-cup. 
The oil-cup has a point to be used as a filling-gauge, and is 
fitted with a tight cover, which carries the flame for ignition of 
the vapors. This apparatus certainly prevents the escape of the lighter 
vapors, but unfortunately the ignition lamp which is attached to the 
cover permanently, and is made of gun-metal, becomes very hot, and 
by communicating its heat to the cover raises the temperature of the 
oil at the sides and surface, and produces results that are too low; z.é., 
this apparatus gives ‘flashing point’ much lower than any other I 
have used, except MANN’S apparatus, which I shall speak of later. 
A very ingenious type of “closed tester” is that devised by BERN- 
STEIN. This consists of a tube in the form of a letter U, which con- 
tains the oil to be tested. One limb of this tube is enlarged, and in it 
is fitted a cap containing two wicks, one central and the other at the 
side. Around the central wick is a tube communicating with the en- 
larged limb of the tube below, and the rest of the cap is closed. To 
operate this apparatus, the limbs of the tube are filled with water to the 
level of the bottom of the larger end; into the larger end a measured 
