The daily morning journal and courier., 1897-05-01
REAL SPERM CANDLES USED
HOW WILLUMINATING POTTER OF GAS
 IS lTEASURED.

Power Not a Mere Expression-An In
 teresting and Instructive Talk With an
 Expert-C Curious Results of Experiments.
 Most people know in a general way that the Illuminating quality of burning gas is measured in candle-power, but few probably are aware that in this city the gas used-at least all used on
 Manhattean Island-is tested every day
 with actual candles, This Is a part of
 the work done by Edward G. Love, the
 analytical chemist employed by the city to keep watch on the gas produced
 by the several companies doing busi-
 ness here. The candles used are of a special quality, and they have 10 be
 just right in order to give satisfaction.
 While not literally made to order they are all imported from England, as none manufactured in this country will fill the bill; they are made of pure sper-
 maceti, mixed with small quantity
 of wax. It takes just six of them to weigh pound, and when lighted they must burn at the rate of 120 grains an hour. A small margin is allowed In this
 matter, and if a candle burns anywhere from IA to 126 grains an hour it is not
 thrown aside, Furthermore, the wick
 must be composed of a certain number
 of strands, with certain number of threads in each strand, and it must
 bend over in such a way that the end will remain just within the edge of the hap1a IUbi1p m, hp t,N n crbt c1ny | ing point must appear. Then, too these candles are required to burn without sputtering when properly protected from draughts.
 The quantity of such candles which the city has to pay for each year is not
 so large as might be supposed. Tn the
 two gas-testing stations the average | number of candles consumed is four
 or five weekly, or a little more than 200 annually. One box of candles contains | 216, and will last close to a year. They
 are taken on approval by the chemist, and if on trial they do not come up to the standard they are promptly re- | jected.
 | When test is about to be made the conical end of the candle is first re-
 moved and then the candle itself is cut | in two. The two pieces are burned at
 one time in the photometric test. I-.e candlestlck forms part of an accurate | balance, so that the rate at which the candles are burned may be accurately
 measured This arrangement is at one | end of the photometer. Near the op- posite end is a gas-burner, into which
 gas from any one of the companies may
 be conveyed at will. At this end also is a gas meter and clock combined, so arranged that the rate at which the gas is being burned may be instantly de- termined. The clock has only single hand, which revolves once minute.
 Another hand revolves apparently on
 the same pivot, but this measures gas, not time. By delicate governor, which controls the gas pressure, the two hands may be made to revolve together, and then the chemist knows that in the ten minutes during which the test con- tinues-a five-foot burner being used one-sixth of five feet has been con- sumed
 The most important part of the pho tometer is the sight box, which is
 placed between the burning candles at
 one end and the burning gas at the
 other. It is here that the human factor enters the problem, for after all, it is the eye of the observer which determin
 es the candle-peWer of the gas. The sight box is so arranged sto slide along
 a graduated scale. On a direct line be- tween the candles and the gas is ground-glass disk, the principal fea- lures of which is numerously pointed star On each side of the star is a small
 mirror, placed at an angle, so that reflections of the star from the opposite side are conveyed to the eye. The pur- pose of the observer is to get the disk in such a position that the two stars, or, rather the, two reflections of the star present the same appearance. When | this is done-and the matter is simple one--the candle-power can be deter
 mined by observing the point on the
 scale marked by the indicator, and
 multiplying it by two, since two candles
 are used If for instance. the indicator reads 1872, the candle-power is 27
 | These are the essential features of the photometers in daily use in the testing
 stations under the direction of MT. Love: there are other details that do
 not need to be mentioned in a general article and various mathematical cal culations are necessary in working out
 the result to nicety The same device | is in use in London, where careful tests
 of gas are constantly made, and In all photometers the arbitrary unit is the light given by one first-class candle. 1 In France the Carcel lamp is employed | "a lamp which burns rape-seed oil or
 colza oil, and gives light equal to nine
 and six tenth English candles. In an
 other lamp sometimes used for testing
 gas, pentane, a light product of petro- | leum, obtained by the redistilling of
 gasoline, is burned
 | In talking with the writer about his
 work for the city, MT. Love said: "The
 gas burned in this country is much bet
 ter than that in England. The usual
 candle-power here is from twenty-two
 to twenty five, but in London they use
 gas of sixteen or seventeen candle-pow- CT What 6 howl there would be here l if such quality of gas were put out by
 the companies! Nearly all the gas for | London is coal gas, but a little camel gas is made of twenty candle-power.
 4 close watch watch is kept on the gas | there, however. and if it falls below the