514 



ILLUMINATION. 



Carbonic acid 

 Subatancei. in cubic fU Heat, part*. 



Tallow 10-1 100 



Wax; spermaceti 8-8 82 



Paraffin candles 6'7 66 



Coal gas 5-0 4T 



Cannelgas 4-0 82 



Kerosene; rock oil 8-0 29 



The great liability, however, of kerosene and 

 other similar and highly carbonaceous oils to 

 escape in part unconsuined -into the air of 

 rooms, in which such materials are burned, 

 constitutes one serious objection to their gen- 

 eral use ; since through pre-occupation of mind 

 in those using it, or through carelessness, this 

 result, with serious contamination of the air, 

 must often occur. In this connection it should 

 be remarked that, the highly dangerous disease 

 known as " spotted fever " (cerebro-spinal men- 

 ingitis), which has appeared at intervals in dif- 

 ferent parts of the country, having recently 

 broken out in very fatal form at Long Branch, 

 N. J., Dr. Sayre, one of a committee of physi- 

 cians who visited the place and examined the 

 cases of fever, names as among the predisposing 

 causes to it the habit in many families of burn- 

 ing kerosene through the night in bedrooms, 

 with the lamp wick put down. Consequences 

 of this practice, to state them somewhat more 

 fully than Dr. Sayre has done, must be the 

 vitiation of the air of the room, not only with 

 tinconsumed oil- vapors, but witR the gas pro- 

 duced by combustion, and often also with some 

 smoke or soot. 



Burners for Kerosene Lamps. The forms of 

 burners and chimneys for kerosene and coal- 

 oil lamps are already very various ; and they 

 are generally so familiarly known that on this 

 head little in the way of novelty is to be ex- 

 pected. It has been desirable to have, espe- 

 cially for chandelier, hall, and bracket lamps, if 

 not for all others, where the use of a chimney is 

 necessary, some arrangement by which the wick 

 can be trimmed and lighted without disturb- 

 ing the chimney or shade. Mr. Homer Wright, 

 of Pittsburg, Pa., has accomplished this end 

 by the invention of a burner with a door in 

 one side, a projection from the inner side of 

 the door and hinged to the front of the wick 

 tube, causing, when the door is opened, by 

 means of a slot arrangement, the wick tube to 

 be at the same time lowered and inclined so 

 that its upper end protrudes through the open- 

 ing, when it can be trimmed or lighted, and as 

 simply returned to its place. 



The inconveniences and expense of glass 

 chimneys for kerosene. lamps have led to many 

 attempts to produce for such lamps cheap and 

 simple burners without chimneys. The prin- 

 ciple of these is generally that of simply ex- 

 tending upward the brass or other metallic 

 tube arrangement which ordinarily surrounds 

 the burner, or forms the cap of the lamp, the 

 burner being carried tip to a proportional 

 height, so that the base of the dame shall be 

 but little below the level of the summit of the 

 tube ; the latter being at the same time freely 

 perforated or mainly open below, and some- 



times also at the sides near the flame, so as to 

 secure an indraught and current of air: the 

 tube of the burner thus becomes itself a short 

 chimney, but mainly placed below, instead of 

 around and above the flame. Among the best 

 known of these, and the most effective, are the 

 so-called "Savage" burner (patented 1862); 

 the "star" burner (J. Edgar 1863) ; and the 

 burner of the " Scoville Manufacturing Com- 

 pany " (patent applied for). Of dealers ques- 

 tioned on this point, one declared that the 

 " star " burner gave the largest clear flame, 

 without risk of vapor or smoke ; another gave 

 preference in the same particulars to the " Sav- 

 age " burner. But all agreed that these burn- 

 ers are in use very inferior for their purposes 

 to the glass chimneys ; that with them a largo 

 free flame cannot be obtained, without its 

 smoking and throwing off unburned oil-vapors 

 into the room. 



Apparatus for Testing the Explosive Pointt 

 of Coal Oils. The subjects of the danger ol' 

 explosion in the burning of coal or rock oils, 

 including kerosene, and of the need of a stand- 

 ard vaporizing point, oils ranging below which 

 shall not be allowed for sale, were considered 

 at some length under ILLUMINATION, in the pre- 

 ceding volume. The need of some convenient 

 and tolerably accurate test of the explosive 

 point of these oils is obvious. 



At first, most dealers simply placed a small 

 quantity of oil in a saucer or other open vessel, 

 dipping in it a thermometer bulb, applying 

 heat, and then by repeated application of a 

 lighted match or taper finding the temperature 

 at which explosion would take place. But, 

 besides the rapid escape or even blowing away 

 of the vapor from over the liquid in this mode, 

 it has other imperfections ; and it almost neces- 

 sarily gives the exploding point higher than it 

 really is thus deceiving the purchaser. 



At least three forms of apparatus for testing 

 more accurately the exploding point of oils 

 have, within the past two years, been invent- 

 ed in this country, the last two of which appe;.r 

 to be those now chiefly in use. The invention 

 of Mr. John Tagliabue, of New. York, consists of 

 a small upright, hollow, cylindrical support, 

 having an opening in the side and below, for in- 

 troducing a gas-burner, or alcohol lamp ; while 

 within the support, above, is a small water- 

 bath, set within which again is a cup open at 

 top to receive the oil to be tested ; into the oil 

 at one side, by a convenient clasp, the bulb of 

 a small thermometer is inserted, while just 

 above the oil a taper is supported this is tx> 

 be lighted when the experiment is commenced. 

 The oil being placed in the open cup, and veiy 

 slowly heated by the lamp removing the h.t- 

 ter at times, if the temperature rise too fast, (X> 

 as to receive for a while the heat only from 

 the water-bath and metals the temperature at 

 which the oil throws off a vapor that mixed wi ;h 

 air explodes is considered to be determined by 

 a slight explosion or "puff," which usually 

 extinguishes the taper. Heating a few degrees 



