from natives taught us that nearly all the blacks had quitted the locality for better-watered areas, we decided that undue risks would attend further examination of the region. So after a short journey to visit Mount Cornish, we profited by the wisdom of the regular inhabitants and made for less arid country. Mount Cornish lies about 8 miles to the west of Twin Heads, and is the most notable hill on that horizon. On arrival it was found to be less than 200 feet high. It seems we were the first white men to reach the spot, and a cairn was erected to mark the event. The most interesting feature in the landscape was a range of hills across the distant western horizon. Running apparently north and south there was a string of seven flat-topped hills, distant about 30 miles. Prescott took cross bearings with prismatic compass on a curious hill, at the southern end, having three peaks. This range is not shown on any official publication that can be found, therefore it may be an addition to the map of the region. Still, one must be guarded in making any claim, for the interior of Australia has been criss-crossed by the trails of bushmen who have wandered without leaving official record. From Mount Cornish we travelled back along our tracks to the Sturt, following it up to the junction of Wolf creek. Along its course we turned westwards once more, still in roadless country, till a team road was eventually joined at Beaudesert station. There the need to take a compass-bearing finally disappeared, and progress was much swifter. After passing Ruby Plains station we joined my itinerary of 1923 close to Mount Barrett, where the main track to the coast was intersected. With the exception of a side trip to visit Mount Dockerell in search of gold, the travelling was commonplace. At Fitzroy Crossing, in view of the excellent tracks ahead, the cars were converted to wheels, with consequent increase in speed. Thirty miles from Derby we crossed the Fitzroy again and joined the track to Broome, where the party arrived on November 22. In the course of four months we had traversed some 2000 miles in the heart of Northern Australia, and had seen every type of country. The cars were shipped to Perth by the same boat that took the rest of the party. I flew south by the weekly aeroplane to make arrangements. me. As I conclude I would like to pay tribute to the men who accompanied Each did his utmost at the task allotted him, and by sticking to the game, often under unpleasant circumstances, showed that spirit of determination which alone has made such expeditions possible. And, finally, it would be amiss to exclude the mechanical transport, that did not fail us on the whole long journey, from this expression of appreciation. Y RECORD OF POSITIONS FIXED BY ASTRONOMICAL OBSERVATIONS IN CONJUNCTION WITH WIRELESS AND OF HEIGHTS ABOVE SEA-LEVEL R. A. Prescott IT would be difficult to imagine better conditions for astronomical work than those which exist in the Northern Territory and Western Australia during the winter and early spring. The nights are beautifully clear and very small stars can be picked out with the telescope, while there are no insects to distract the observer. The instruments which the Royal Geographical Society kindly lent to us were as follows: one 6-inch theodolite with micrometers in two cases; one prismatic compass; one aneroid barometer reading up to 10,000 feet; one boiling-point apparatus; one 6-inch sextant and artificial horizon; two half-chronometer watches. The wireless receiver we had was a three-valve set, with one stage of high frequency, one detector, and one stage of low frequency amplification. It was made by Messrs. Gambrell & Sons, 76, Victoria Street, who arranged it most compactly with spare batteries, in a shut-up box with no external parts to be injured. I used rubber-insulated wire for an aerial rigged between two trees, by cords slung over branches. The earth consisted of 20 feet of ordinary wire netting, with wire soldered to it, spread out on the ground with sticks and stones thrown on to keep it flat. The receiver was a great success, and I picked up the time signals on most nights from Perth and Adelaide at distances up to 1800 miles, but nothing could be heard in the daytime. Dry batteries were used throughout-two Hellesen 1 cells for the lowtension supply, and the spares were never used. Since I got back to England I have had well over one hundred hours of work from these two spare batteries, which were nearly nine months in the tropics, and I think that they would do excellently for lighting a theodolite. The observations were nearly all taken at night, and whenever possible results are by means of pairs of E. and W. or N. and S. stars. Stars were observed at an altitude of from 30° to 55°. The shimmer of the atmosphere made it very difficult to observe a point accurately during the day. The greatest difference between latitudes by N. and S. stars was 5′′, while the difference between longitudes by E. and W. stars was 15′′, except in the case of "Swan River Water-holes," which was fixed by a.m. and p.m. observations of the sun, which differed by 50′′. I observed for azimuth at intervals along the route, and the results approximated to the figures on the charts, and my last observation for azimuth near Godfrey's Tank gave a mean result, from E. and W. stars, of 2° 34′ 4′′ E.. the two observations differing by 17". My last observation for longitude on our journey westward was at Well C. 28 near Godfrey's Tank, which I made almost exactly 126° 31′ E., which is further west of the position usually marked on maps. Mr. Canning's position is about 126° 37′ E., while Mr. Carnegie, who discovered Godfrey's Tank (2 miles east from the well), gives that position by dead reckoning as 126° 25′ E. Our latitude positions agree very closely, about 20° 15′ S. It was difficult to find a good place in which to keep the two half-chronometer watches. To begin with, I carried one in a pouch at my belt and the other in a box just behind the driver's seat of the car in which I travelled. Mr. Reeves handed over both these watches to me with a most satisfactory rate, but for some reason the one I wore began to give trouble as soon as we got out into the bush. This may have been due to the jars it received whenever I made the 4-foot jump to the ground out of the car, a thing I had to do fairly often to take note of the mileage between places registered by the mileometer fitted on the front wheel of each car. When the time signals began coming in, I found that this watch had a very large rate. Left with one watch, I decided to take no chances as to the cause of the trouble, and so left the other watch in its pouch hanging up inside the box, where it maintained a fairly good rate during the whole journey. Its companion never recovered. The aneroid was new and gave very good service. It was easy to read to hundredths of an inch, and seemed to be unaffected by the shaking and rattling it received. Having started its career with a certificate showing no error, it was pronounced by the authorities at the Perth Observatory to be still without error at the end of the journey. Furthermore, I had an opportunity to check it at Halls Creek by two readings which gave a result differing but little from the accepted height of this place. The heights are worked out with Derby as a base station from readings for the same dates and hours kindly supplied to me by the Meteorological Office at Perth, and each place is fixed by means of at least two readings on separate days, and in many cases by means of many readings on different days. The difference between heights of which a mean was taken varies from 10 to 150 feet. I have discarded a few readings which for some reason or other were evidently widely in error. I think it is interesting that my observations fix Gregory's Salt Sea at 1000 feet above sea-level. From this "Sea," which lies in a slight basin, the country rises gradually towards the west until the highest point is reached at the cliffs above Godfrey's Tank. The country beyond these cliffs, which run roughly north and south, appears to have sunk or broken away, and is at least 300 feet lower. The sand-ridges, which ran on a bearing of 92° whenever we encountered them, are discontinued for about a mile and then start again as soon as they get out from under the lee of the cliff. They then continue over nearly level country to Mount Cornish, which, by the way, is marked considerably out of place on the map we had, and is really a small hillock rising 90 feet sheer out of the slight rise on which it stands. A mile and a half farther west a very much smaller breakaway occurs, beyond which the sand-ridges continue as far as the eye can follow them. About 30 miles away on a bearing of 267° from the cairn we built on top of Mount Cornish a curious three-peaked hill is visible, and farther north other small hills and a low range. I think it possible that another breakaway or stepdown occurs at that point. I kept careful record of mileages and rough directions until we started steering by compass among the sandhills. The tracks which we had been following previously turned and twisted so much that it was impossible to keep accurate records of direction in the scrub. At first it was very cold at night and in the early morning, and the temperature must have fallen often below freezing-point. The lowest temperature I recorded was 35° F. after the sun had risen at Bull Creek in the Northern Territory on 28 July 1925. The atmosphere is intensely dry, and anything wooden is liable to shrinkage and distortion. A parallel ruler became useless almost at once, and gaping cracks appeared in the theodolite boxes, letting in much dust and dirt. LIST OF POSITIONS FIXED BY ASTRONOMICAL OBSERVATIONS IN CONJUNCTION WITH WIRELESS IN THE NORTHERN TERRITORY AND WESTERN AUSTRALIA N SOME EARLY COUNTY MAPS Edward Heawood, Librarian, R.G.S. OT till well on in the sixteenth century did the rough general maps previously in use begin to give place to more detailed and accurate representations based on actual field-work. A movement in this direction then set in almost simultaneously in the principal European |