THE “SCARAB” OIL BURNER
With respect to the use of the fuel oil direct under pressure, this system generally involves the heating of the fuel oil, as well as its filtration, the fuel being supplied under pressure by means of pumps. The system is extensively employed at the present time on marine boilers operating with forced or induced draught, and, in this connection, the Wallsend system stands pre-eminent.
Since writing the first edition of this little volume considerable advance has been made in connection with the use of oil fuel for general power-raising purposes, and much of this expansion has been consequent upon the introduction of a new burner—the “Scarab”—which is here illustrated. It is the invention of Lieut.-Col. Macdonald, and is the outcome of the war. When the Lieut.-Colonel was on service in Mesopotamia, he recognized the possibilities of oil fuel, for while wood and coal were being transported from India at great cost, oil was running to waste on the neighbouring fields of the Anglo Persian Oil Company. The Lieut.-Colonel therefore introduced a method of cooking by oil fuel, and immediately on his return to England he carried out experiments which led to the introduction of the “Scarab” burner. It is a simple contrivance, and is practically fool-proof, since there are really no parts to get out of order. The oil fuel flows through a tube by gravity, while another tube carries air compressed to about 10 lbs. pressure. The oil and air meet some inches distant from the mouth of the burner, and the combustion of the fuel, which is turned into a finely atomised spray, is complete. Experiments have been made with the burner for domestic purposes, and it has been adopted already in several London hotels for cooking purposes, though its general application is practically unlimited.
CHAPTER VII
PETROLEUM AS A LIGHTING AND COOKING AGENT
From times immemorial, petroleum has been utilized as a lighting agent. Fifteen hundred years ago we have records of its use in the Far Eastern countries, and in the seventh century one of the Emperors of Japan ordered that his temples should be illuminated by the sacred oil light. And from that long distant date to the present times, petroleum has played a not insignificant part in the provision of artificial light throughout the world. For centuries, petroleum, as a means of artificial light, had the field to itself, and, though the Ancients consumed large quantities for lighting purposes, the apparatus used for burning the oil were of a most primitive type, giving results which to-day would be considered far from satisfactory.
About the middle of the last century, when the petroleum industry was making steady advance in several European countries, and a little later, when the United States entered upon its era of oil progress, there was marked development in the use of oil for lighting purposes. The more modern oil lamp was introduced, and it is worthy of record that in one year alone over fifty patents were taken out in the United States for oil lamp improvements. The Germans, too, were not behind in this respect; in fact, it is very largely due to the numerous German improvements that the general governing principles of present-day oil lamps became so popular.
There is no doubt that the ordinary oil lamp has often been, and still is, unjustifiably condemned for certain defects which are not inherent in it. It necessarily demands attention if it is to give a satisfactory light, but, unfortunately, this attention is not adequately bestowed upon it, and complaints are the result. I have frequently argued that, just as it is possible with inattention to make the most improved pattern of oil lamp operate unsatisfactorily, so is it possible, with a little care and common sense, to get a really good and satisfactory light from the cheapest oil lamp obtainable.
In days gone by, the quality of the oil was, in many cases, unsuitable for burning in the ordinary lamps; its lighting power was very inferior, and it gave off a distinctly unpleasant smell. To-day, however, the illuminating oil sold throughout the world is a first-class article, and its flash-point has been so raised that it can be used freely without there being any suggestion of its lack of safety. One still hears of the “dangerous” paraffin lamp, but, to all intents and purposes, whatever danger was attendant upon the use of oil lamps has long ago departed, though, of course, care must always be exercised, a remark which naturally applies to every illuminant. It is not within my province to give a series of hints to the ordinary user of illuminating oil, but it is well to draw attention to a point which is frequently overlooked: that is, to see that lamps should be kept well filled. It has been established that the light from an oil lamp is greatly affected by the quantity of oil in the reservoir. An increase of 20 per cent. can be secured in the illuminating power of the lamp if only the oil is kept to a good level in the container. This is due to the assistance given to the capillary action of the wick by the higher level.
The advent of gas, and, at a later period, electric current, for illuminating purposes has, to an extent, restricted the use of oil as an illuminant, yet the reader will be surprised to learn that at least 2,000,000 oil lamps are nightly lighted throughout Great Britain. The inhabitants of the majority of our villages have to fall back upon oil lamps after nightfall, and even in remote spots where enterprising gas companies have laid gas mains large numbers still keep faith with oil, no doubt by reason of its cheapness in normal times.
The greatest improvement made in regard to oil lighting has been in connection with the introduction of the incandescent mantle. As a result of this innovation, several elaborate designs of lamps have been placed on the market, and to-day oil is frequently used in large residences in preference to the more modern illuminants. This is due, without doubt, to the fact that oil light is particularly soft, and, while giving a great illuminating power when consumed under the best conditions, lacks that dazzling brilliancy which causes injury to the eyes.