The electricity required for heating purposes is supplied by a 1,000-watt engine-driven generater, will serve not only the crew (warmin~ their clothing and even their goggles so that these may not become frosted), but also the valves of the oxygen apparatus, deli instruments as might ' cease " to operate if they became frozen, The pilot i ill have need Of this is no roof, is equipped with wind-screen and. is inst the draughts into a pilot's cock-
machine; yet, he will still remain th the forward part of the most exposed member of the and-upon his ability to continue his work will depend the safety of him self and his observer, One other important - yrovislair Atade. in, the_interésts of efficiency thas been the fitting of spring control boxes on the control cables to take up the differential contraction of the steel as compared with the duralumin inthe aeroplane strueture, The control cables are of whereas the wings and. most of the frame are of duralumin, which contracts in changing te perature about twice ae much as The other aeroplane is the West-jand Wallace, the standard general purpose aircraft. It is fitted with a Bristol Pegasus (580 lip.) engine, A similar engine boosted to a higher degree was used-by Captain C.F. Uwi when he made his altitude record. It embodies two devices—a ssu charger and an automatic boost control—which react on each other in such a way that the output ut the engine remains nearly constant throughout a large part of the climb. 'That is to say, a centrifugal fan compresses the gases before entry into' the cylinder, and a wrograph controls a servo-motor which in tum controls. the opening, Of the throttle and thus prevents the fan from overcharging ths cylinders. The Wallace, which is similar i general design and in many details to the Houston-West-Tand, has been adapted and equipped in exactly the same way, and expected that two " mi chines will have performances nearly equal that there will be little aificulty in their carrying out the expedition together.
<The flight will almost certainly, slart, early in the day, because the fake-off will be easier in the cool hnorning air, and the comparatively bad conditions which are found in the middle of the day will be of less importance when the machines fare Janding light at the termination of their flight, It will be essential to choose @ day when the sky. is clear and. visibility is good for the whole flight. Weather forecasts will be made available by the courtesy of the Director-General of Meteorology, India. In the hest conditions" the 29.14ift. actual height of Mount Everest' will, om account of its southern latitude, represent a standard atmosphere height of about 30,500%t. In the worst possible conditions this might 2 rise to $1,500ft,, but in such a case the weather would probably be so bad that the flight could: not_be undertaken. 'The' aeroplane: are expected to give us a height of
Text read from the printed page and cleaned; old type leaves the occasional error.