464 



KEROSENE, IMPROVED TEST FOR DANGEROUS. 



range of agricultural products known to the temperate 

 zone ; that one half of our primitive forests abound- 

 ing in the greatest variety of valuable timbers is still 

 untouched ; that our State abounds in the richest iron- 

 ores to be found in the world ; and that our coal area 

 is more extensive than that of the great State of Penn- 

 sylvania, or of Great Britain and Ireland combined, 

 underlying nearly 13,000 square miles. 



The Southern Exposition. The Southern Ex- 

 position opened at Louisville, Aug. 1st, and 

 continued one hundred days. The subscribers 

 to the capital stock numbered 1,722, and the 

 total amount of subscriptions was $258,122. 

 A building covering thirteen acres and costing 

 $300,000 was erected. The number of exhibits 

 was 1,500, classified in groups and departments, 

 arranged with reference to similarity of char- 

 acter. Premiums in money to the amount of 

 $6,750 were distributed for displays of cotton. 

 In the general awards, 109 diplomas, 221 cer- 

 tificates, and 478 medals were adjudged to 

 successful exhibitors. The total number of 

 admissions was 770,048. The best attendance 

 was from Sept. 10th to Oct. 20th, at which 

 time several other expositions in different parts 

 of the country were in operation. Although 

 the Southern Exposition was not wholly sat- 

 isfactory in a financial way, the stockholders 

 felt warranted in increasing their capital to 

 $500,000, with the intention of holding another 

 exhibition in 1884. 



Miscellaneous. A National Convention of Col- 

 ored Men met in Louisville Sept. 24th, and dis- 

 cussed and acted upon civil and political rights, 

 education, and labor. 



KEROSENE, IMPROVED TEST FOR DANGEROUS. 

 The dangerous properties of kerosene are 

 derived from the presence in the 

 oil of the extremely volatile con- 

 stituents, benzine and naphtha. 

 These substances are easily ig- 

 nited, and alone, or mixed in 

 small proportion with kerosene, 

 readily emit vapors which are 

 highly inflammable, and which 

 form with air an explosive mixt- 

 ure. Kerosene is safe only when 

 it will not yield these dangerous 

 vapors at any temperature which 

 it is liable to assume. This tem- 

 perature depends partly upon the 

 warmth of the place where the oil 

 is kept or used, and partly upon 

 the heat of the burning wick warm- 

 ing the oil in the reservoir of the 

 lamp. It has been found by ex- 

 periment that the maximum in- 

 crease of temperature of the oil 

 in a burning lamp is about 16 

 Fahr. It is possible for oil to 

 have in summer a temperature of 

 from 90 to 100 in the unlighted 

 lamp, and in winter a still higher 

 temperature, if the lamp is near 

 a stove or an open fire. Hence the lowest 

 temperature at which an oil may evolve in- 

 flammable vapors and be considered safe must 



be put at 116, or, better still, at 120 Fahr. In 

 testing oils a distinction is made between the 

 flashing-point and the turning-point. The 

 flashing-point is the temperature at which, when 

 the oil is slowly heated, the vapors escaping 

 from it will first take fire with a slight explo- 

 sion when a lighted match is passed just over 

 the surface of the liquid. It marks the tem- 

 perature at which the oil becomes dangerous. 

 The heating may be continued till a point is 

 reached at which the oil will take fire and con- 

 tinue burning by itself. This is known as the 

 burning-point. The flashing-point is easily al- 

 tered by trifling variations in the conditions, 

 as in the quantity of oil used, the rate of heat- 

 ing, the range of temperature through which 

 the oil is heated, and the distance above the 

 surface at which the match passes. The burn- 

 ing-point, upon which the ordinary fire-test is 

 based, is of little value; for not only does it al- 

 ways lie above the flashing-point, but it bears 

 no simple relation to the latter, and the deter- 

 mination of it gives really no clew to the tem- 

 perature at which the oil becomes unsafe. 

 Some twenty-five different instruments have 

 been proposed for ascertaining the lowest flash- 

 ing-point of a sample of oil, all of which are 

 based upon the principle of slowly heating the 

 oil till its vapor will take fire on passing a match 

 or other igniting agent over it. Engler and 

 Haas have laid down seven principles to which 

 all such testing apparatus and experiments with 

 them, to be of any value, must conform, viz. : 

 1. The quantity of oil must be the same in all 

 experiments. In the Saybolt tester, which has 

 been adopted by the New York Produce EX- 



FIG. 1. SAYBOLT TESTER. 



change (Fig. 1), variations of one twenty-fifth 

 of one inch cause differences of some degrees in 

 the flashing-point ; 2, the oil must be heated 



