DISCOURSE OF W. B. TAYLOR. 313 



aration in later years by liigh distillation, seemed to justify the 

 attempt. Not only was a laborious inquiry into the best conditions 

 of combustion, by precise photometric measurement required, but 

 for the security of the service, equally laborious examinations into 

 the best practicable methods of testing, of handling, and of storing 

 this material.* To secure a proper oxygenation 'in burning, a 

 modification of the lamp was required. "It was soon apjjarent 

 that the use of mineral oil would necessitate a change of lamps, 

 and attention is now directed to the perfection of one which will 

 produce the best results from this illuminant. It is thought that 

 the lamps now used with lard oil can be converted at no great 

 expense and successfully used with mineral oil. Our experiments 

 liave shown that this oil can be more readily used in the smaller 

 lamps; and it is proposed as soon as suitable ones can be jjrepared, 

 to put it into use at such stations of the fifth and sixth order, as 

 may be thought expedient; when if it be found satisfactory, an 

 attempt will be made to substitute it for lard oil in lamps of the 

 higher orders." f "This change is proposed entirely with reference 

 to economy; for it has been found by repeated experiment, that 

 while a somewhat su[)erior light may be o))tained from a small 

 lamp charged with kerosene, a larger lamp charged with lard oil 

 affords the greater illuminating power. So great is this difference 

 in lamps of the first order with five wicks, that the rates of light 

 from kerosene and lard, are as three to four respectively. Since 

 the safety of the keeper and the continuity of the light are essen- 

 tial elements in the choice of an illuminant, a thorough acquaint- 

 ance with the nature of the substance is essentially necessary. 

 With a view therefore to the introduction of kerosene, a series of 

 experiments have been made during the last two years on the 

 different varieties of this material found in the market." | 



*"It has been estabUshed that the ordinary flre-test Is Insufficient as usually 

 applied, and that an explosive mixture may be formed by confining the vapors 

 given oflT at a temperature In soine cases twenty degrees lower than that certified 

 to by the public Inspector. That this Inquiry Is of great practical Importance to 

 the Light-house system, must be evident when we reflect that means must be 

 ilevlscd for testing the oil offered for acceptance In accordance with contracts; 

 for storing It; for transporting it to light-house stations; Jbr preserving It in 

 butts at the stations ; and for the instruction of the lieepers in Its dally use." 

 iReporl of L. H. Board, 1877, p. 5.) 



t Report of L. H. Board, 1875, p. 6. 



X Report of L. 11. Board, 1877, p. 4. 



