Science. Fairy Rings. The dark, green circles of grass known as " fairy rings " have long attracted the notice of scientists, but Messrs. Lawes, Gilbert, and Warington, of Rothamstead, have probably given us the true explanation of the phenomenon at last. The luxuriance of the grass is due to nitrogen, that potent fertiliser, which is abstracted from the surrounding soil by the fungus plants in the ring. The grass in turn feeds on the minerals collected by the fungi, thus obeying the principles of the rotation of crops. It was not proved before that any kind of plant could feed directly on the organic nitrogen of the soil;

Waikato Times, Volume XXIII, Issue 1914, 11 October 1884, Page 2 (Supplement)

Science.

Fairy Rings. The dark, green circles of grass known as " fairy rings " have long attracted the notice of scientists, but Messrs. Lawes, Gilbert, and Warington, of Rothamstead, have probably given us the true explanation of the phenomenon at last. The luxuriance of the grass is due to nitrogen, that potent fertiliser, which is abstracted from the surrounding soil by the fungus plants in the ring. The grass in turn feeds on the minerals collected by the fungi, thus obeying the principles of the rotation of crops. It was not proved before that any kind of plant could feed directly on the organic nitrogen of the soil ;

T2i© Phonograpli and Languages. An interesting experiment with the phonograph, which will b^ its first practical application, is about to bo made by Drs. Zintgraff and Chavanne, two explorers who are about to visit tho Congo region. They intend to fix the language and melodies of tribes they may meet with, and send the record homo to Germany for tho edification of scientific men there. The apparatus u being made by Herr Fuhrraanu, of Berlin ; and if the instrument is successful with the German language, it may well succeed with another.

Electric Lijslit from tlie Seine. The municipal council of Rouen are about to use ttie current of to j Seine to drive a set of dynamo-eleetrio machines, which will supply current to maintain -i powerful electric lamp placed on the towti- of the cathedral, and having its rays reflected downwards on the city.

The Oci'JU'e-Cycle. A new roadster jCouibining speed and simplicity of the ordinary bicycle with the safety and stability of the tricycle, has been devised by Mr. E. Burrow. It has one large wheel like a bicycle, but that 13 supplemented by four smaller wheels, two in front and two behind the driving-wheel. Tne action is similar to that of a roller-skate, and the steering is ingeniously effected. Moreover the apparatus is at will convertible into an ordinary bicycle.

Ail Electric Microscope. An interesting exhibition of microscopic views of objects projected on a screen by means of the electric light was recently introduced from Paris at the Crystal Palace. To show how much the views are enlarged, a section of a butterfly's wing occupied the whole screen which took up one aide of the entertainment court. The eye of a fly is magnified no leas than four million times it 3 natural size.

A New BaXEooia. Mr. Ciurles F. Eitchkl, an American, has invented a balloon which can be raised or lowered at pleasure, without either throwing out ballast or loosing gas. The balloon consists of a horizontal cylinder with square ends, to which is attached a netting six feet wide and as long a3 the balloon. Under this is a series of canvas shuttera lapping over one another, and opened or closed by a screw propeller worked by hand. When the shutters , are closed they offer resistance to the air, when open they allow the balloon to riae. The action of the propeller gives an upward or downward motion, according to the direction in which it is revolved.

Magnetised Watches. Since the introduction of the electric light, a great many good watches, especially those with English lever balances, have been ruined as time-keepers by magnetism induced in their steel parts, through the wearer going too near the poles of a dynamo machine. Professor G. Forbes, an electrician, had a gold chronometer watch, which formerly kept excellent time, so far destroyed as to lose several minutes a day; and we hear of watches actually losing twenty minutes in the hour. Mr. Forbes investigated the cause of the losing rate, and found it due' to the bar of the lever being magnetised,,and also some iron screws in the works. Probably, too, the hair-spring was magnetic. The chronometer has been cured by removing' the balance, springs, and screws, and substituting others of nonmagnetic metal. The balance is now of platinum-iridium (platinum-silver being too soft and subject to shocks) and the sprin gis of gold. Brass may be used for the screws, provided it is found to be non-magnetic, but some kinds of brass are magnetic, perhaps through admixture with iron. We may also mention /that cases of soft iron were sold at the Vienna i Electrical Exhibition, for the protection of existing watches; the iron shell forming a magnetio screen or shield.

and the explanation of the fairy ring may lead to advances in agricultural chemistry.

A New Police Whistle. The whistle recently supplied to the Metropolitan Police force, as the means of calling in the aid of brother officers to one in danger or need of help, may now be bought by the general public, to whom it is likely to prove useful. The note of the whistle is quite diatinct from that of any other in use, and is very penetrating. If the policeman should be anywhere within range when the new whistle is sounded, he would, for his own sake, we think, make an effort to find the cause, for the noisa is almost ear-splitting.— Cassefs Magazine.

Sinking Shafts by Freezing. An ingenious mode of sinking shafts in quicksand or other shifting ground has been devised by Herr Poßfcsch, and is being introduced into this country. It consists in freezing the soft ground hard by a freezing mixture, and then excavating it in the ordinary way. The refrigerator is of the ammonia type by preference, but any sort will do; and the temperature employed is about 15 deg. below zera Fahrenheit. When the quicksort is frozen hard the excavation is carried on in the usual manner, and 3 a masonry or iron-tube lining is given to the shaft-hole.