one of 24lb., which buried itself 6in. deep. The furthest pieces were six miles apart; and the luminous passage of the meteor, which was very brilliant in spite of bright sunlight, was seen by many observers. A very bright meteor was seen on October 1st, 1917, over an area extending from the N. of England to Somerset, and others on September 23rd, and other September dates, October 18th, and October 23rd. The standard time in New Zealand has hitherto been 11 hours in advance of Greenwich time; but it has now been decided, in order to bring it into uniformity with international arrangements, that it shall be exactly 12 hours in advance of G.M.T. In timekeeping at sea, the practice has been to alter the clock whenever an observation chances to be made, which led to much uncertainty. It has now been settled that the time should be altered regularly on passing a meridian the time on which differed by an integral number of hour from Greenwich time. The great telescope at Mount Wilson, which is nearly ready for use, has a mirror 101.2in. in diameter, and is expected to render visible 300,000,000 stars.

METEOROLOGY.

Weather conditions for 1917, taking the results of the whole year, were not very different from the normal, the mean temperature at Greenwich, 49 degrees, being only half a degree less than the average, and the rainfall, 25. 3in., being 1.5in. more than the average amount. Snow fell at Greenwich on no less than 51 days, of which 16 were in January. The fall, as measured in my rain gauge at Montevideo, Chickerell, was 22.92in., nearly 7 inches below the average for 18 years (29.63in.), the months of January, February, November, and December producing a total fall of only 4.87in., an amount which is often exceeded in one of these months alone. Some other parts of the British Isles, especially the East Midlands of Scotland, had a dry year. The winter of 1916-17 was, as will be remembered, exceptionally long and cold, whereas last winter was distinctly mild. August was unusually

wet and stormy everywhere, and at Montevideo was, with the exception of October, the wettest month of the year. One of the greatest falls during a thunderstorm in the London districts was experienced on June 16th, 1917, when amounts up to 3.37in. were measured between 5 and 7 p.m., which has only been exceeded in that locality in the same interval, by 3.42 on July 23rd, 1903, and 3.90 on April 10th, 1878. Here there was a good deal of thunder between May 26th and June 19th. On the night of March 7th there was a fine display of aurora in the neighbourhood of London and other more northerly places. This coincided with a large magnetic disturbance, which reached its greatest intensity at about 2 a.m. on March 8th. It is suggested that this disturbance was connected with the large magnetic storm of December 16th-17th, 1917, there having been repetitions on January 12th and February 8th, the interval in each case being 27 days. Some instances of rainbows caused by the rays of the sun being reflected from the surface of water have been recorded. In such cases the usual two rainbows are generally seen, and also portions of another pair, which cut the first two at the horizon and comprise much larger arcs of circles of similar sizes. After more than 3 years of war, opinions are still divided as to whether the rainfall is or is not influenced by gunfire, the evidence being very inconclusive on the subject.

ELECTRICITY.

The magnetic storms of December 16th, 1917, and March 7th, 1918, have already been alluded to. Another of considerable magnitude occurred on August 9th-10th, and was also noted from Australia, where it was accompanied by a display of aurora. The magnetic survey work of the "Carnegie," which in the winter of 1916-17 surveyed the portions of the ocean between San Francisco and Easter Island, and thence to Buenos Ayres, shows that the errors of the British Admiralty charts in the first portion are less than half a degree, and slightly more in most of the second portion from Easter Island

to Buenos Ayres. Round Cape Horn the charts are practically correct. A Report on the magnetic survey of New Zealand, which was commenced in 1899, has also been lately published, Further experiments in electrifying crops have been made in Dumfries with satisfactory results. The electricity was applied from overhead wires, and the crops of oats subjected to it produced 49 per cent. more in grain and 88 per cent. in straw than crops grown in adjacent patches in the ordinary way. Furthermore, crops of clover grown after the oats were much improved, though the electricity was discontinued. The extra profit was £6 7s. and the cost of electricity only 11s. for the acre so treated. In connection with this subject, my niece, Miss Rogers, tells me that at Hampstead, where she lives, the trees and shrubs near the road electric lights always come out before those further away, and that in the last two years, when the electric lights have not been used, this difference in time of shooting has not taken place. Boats controlled by wireless electricity have been used in the war. Fog signals are also worked in this way, the machine being started by wireless at the beginning of a fog and continuing to explode automatically at intervals until stopped.

CHEMISTRY.

One of the many important industries which have necessarily developed or greatly increased in this country since the war, and in which we have hitherto depended chiefly on German supplies, is that of dyeing. In 1915 "British Dyes, Ltd," was started with a capital of £2,000,000, and lately the Government has sanctioned a scheme involving an expenditure of several millions of pounds. There is probably much in regard to dyes which we do not know, and the services of research chemists will be most valuable. America has also made great strides in supplying itself with the dyes which it cannot now import. An Australian Chemical Institute has been formed, with its headquarters in Sydney, with the object of advancing the science generally, holding examinations

and granting certificates of competency. Analyses of the ashes of a number of different plants have shewn the presence in the plants of minute quantities of some of the rare elements, such as lithium, rubidium, caesium, chromium, vanadium, barium, strontium, and titanium. Aluminium, lithium, and rubidium were practically always present. In these experiments the earth in which the plants were grown contained traces of the elements found in them. As regards the production of nitric acid, ammonia, and other useful chemicals from waste products, some progress has been made, as well as in the fixation of the nitrogen contained in the air, though this latter has not yet taken a practical form in this country. Some substitutes for platinum, which has now reached a value of about five times that of gold, have been discovered and can be used for certain purposes. They are mostly compounds of gold with iridium, titanium, or other metals.

ENGINEERING.

The Report of the Advisory Committee for Aeronautics for the year 1916-7 has lately been issued, and deals with much experimental work that has been carried out with regard to aeroplanes both in their structure and materials, and in their behaviour in flight. One great difficulty is that of finding the course when the earth is hidden by clouds, as the aviator is unable to perceive the effect of the wind which carries him out of his direct line. Our aeroplanes seem to have improved very much of late and to have quite the upper hand of the German ones, from the relative numbers of those destroyed which are published in the newspaper reports. A flight of 650 miles, from Turin to London, was made on September 24th last, the journey occupying 7 hours 20 minutes, a rate of 89 miles per hour. The same aviator had previously made a flight of 920 miles without stopping, from Turin to Naples and back, -a fine record. The use of aeroplanes for postage and commercial purposes after the war is being considered, and it has been calculated that

parcels can be thus carried from London to Paris in 3 hours at a charge of a halfpenny an ounce so as to leave a profit. One of the most sensational surprises which the Germans have given us is the long range gun used to bombard Paris from a distance of 75 miles. It is considered that the shell must traverse for a large portion of its course, high parts of the atmosphere of extreme tenuity where the resistance is small, and that the initial velocity must be about 5,000 feet per second. The great demands on steel for war purposes have led to the building of wooden ships in America for freight purposes, but in this country wood is probably too scarce at present to be thus used, and the output of steel has been greatly increased since the war began. Another material which has been used is reinforced concrete, but time is required to shew how far this is trustworthy. It is strong when used for buildings, but liable to cracks under strain. The work of lifting into position the central span of the Quebec bridge was successfully completed last September, the weight being 5,000 tons and the height 150 feet. Another large work lately finished is the Arrowrock dam in Idaho, U.S.A., which is 348 feet high, 1,100 feet long, and 140 feet thick at the base and composed of reinforced concrete. In the present difficulty about coal, the water power available in the various countries is assuming more importance. In England this is unfortunately very limited, being estimated at only 396,000 horse-power as against 9,200,000 in France, and somewhat smaller amounts in other countries. Experiments have shewn that one of the best methods of storing coal is under water, in which case it suffers no deterioration. Coal gas stored in cylinders or otherwise has in some cases taken the place of petrol for motor omnibuses and taxis, and is probably capable of further development, 250 c. feet of gas being about an equivalent of one gallon of petrol. A prize of £1,000 has been offered by the Automobile Association in connection with this subject. It seems doubtful whether petroleum exists under the surface in this country, but there seems some prospect of attempts being made to