Passing Comments
Page 24
Page 25
If you've noticed an error in this article please click here to report it so we can fix it.
T"value of high-precision overhaul work required by law in aeroplane practice is being recognized in other fields. Some commercial-vehicle engines are now being sent for overhaul to aeroengine specialists, who work to A.I.D. standards and cylinder finishes within .0002 in. error.
TRAVELLERS on the Empire routes of Imperial
Airways, Ltd., frequently remark that the valuable time-saving of the air mail is accomplished not in a breathless rush but in stages which give time to see something of the places en route. In fact, it is the nightly break in the long journey which robs it of monotony and fatigue, for every night is spent in a comfortable airport. IN the course of recent road tests of up-to-date oil-engined chassis, our staff have been impressed by the unquestionable superiority of their brakes over those of even modern private cars. Car owners on the road show surprise at the performance of these commercial chassis and sometimes stop to watch them being tested.
IT is not always easy for a driver to discern the
lines marked on the roads to indicate crossing points for pedestrians, and in this connection Chelsea Borough Council is recommended to prepare some experimental road sections consisting of black and white granite blocks measuring, superficially, 18 ins. by 12 ins. MANY difficulties beset the pioneers of the pro duction of benzole. A scare was circulated to the effect that this fuel pitted cylinder walls. This was possibly true of " unwashed" spirit, but not of good-quality fuel, and it took a considerable time to clear the air of rumours of this class.
LANCASHIRE is particularly interested in the subject of the production of benzole in this country, because some of the earliest experiments in this direction were made in that county. Benzole was produced at Bridgewater Collieries, Walkden, near Manchester, about 28 years ago, under the supervision of Dr. Berry, who, later, continued his experiments in North Yorkshire. The price, for some time, was 7id. per gallon. One of our Manchester correspondents rode Dr. Berry's benzoicfuel motorcycle, believed to be the first machine of this type to use home-produced spirit.
MANY users of high-speed compression-ignition
engines, equipped with heater plugs for starting up, might be excusably surprised to learn of the simple means employed on the Marshall agricultural tractor for accomplishing the same object. A cartridge starter is used. It consists of a strip of saltpetre-impregnated paper twisted around a plain plug, which is ignited and screwed into the combustion chamber, where it smoulders and generates enough heat to induce combustion of the initial charge. Of course, such a system would hardly be suitable for small-bore high-speed engines, but it is ideal for the rough usages of agriculture.
IN the making of maps from aero photographs, ' what, at first sight, would appear to be an insuperable difficulty is the marking of altitudes. Such is not the case, however, for, by an ingenious method, employing the stereoscopic principle, an accurate indication of variations in height is obtained, which enables the cartographer to place the contour lines with a completely satisfactory degree of precision, WE LEARN from Dr. Rudolf Diesel that the French manuscript of his father's book, "Theory and Construction of a Rational Heat Motor," which appeared in 1893, is being offered for sale. The manuscript throughout is in Dr. Diesel's own handwriting, and its already considerable value should increase. Possibly some important maker of compression-ignition engines would like to possess such an historic document IN view of the fairly common practice of using oil
fuel for cleaning purposes, the words of Sir John Cadman, during his lecture on Science in the Petroleum Industry at the Royal Institution recently, to members of the World Petroleum Congress, have considerable significance. Apropos the practiceof the Anglo-Persian Oil Co., Ltd., of returning surplus oil to the reservoir, he deplored the waste which occurred when oil fuel was consumed merely because its price was low, regardless of its real potentiali ties. Reserves of petroleum were limited, he reminded his audience, and it would be as well for posterity if such products were used solely for those purposes to which they were best fitted.