THE MONTH: SCIENCE AND ARTS.

The Royal Agricultural Society's Journal, No. 25, recently published, abounds with information likely to interest other persons as well as farmers. There is a good account of the implements exhibited at the Philadelphia Centennial Show, in which many clever contrivances are described, among them not a few shewing that Canada is by no means deficient in inventive ingenuity. Dr Voelcker in his experiments on roots explains that swedes when allowed to sprout a second time transfer two-thirds of their solid substance to their tops or leaves; and he calls attention to a series of experiments carried on in France which lead to the conclusion that 'roots mature more readily when planted closer, and often yield a heavier crop per acre, than when they are planted too widely apart.' In his chemical report the doctor exposes the trickery used in the manufacture of oil-cake, and says that he has 'considered it his duty to refer to these matters because he knows that mal-practices of cake crushers and dealers are again gradually extending all over England.' Then comes an article on the use and value of straw as food, which will surprise most readers; and next we find a Report on analysis of butter drawn up for the Board of Inland Revenue, in which the reporters state that the more butter is washed and kneaded to expel the curd the better will it be; and that 'while some of the finest and best prepared butters undergo little or no change, there is in others a gradual disappearance of the characteristic principles of butter, and a consequent assimilation to the constitution of an ordinary animal fat. This change, which appears to be due to an incipient fermentation, and is generally accompanied by the development of fungi, is probably caused either by the use of sour cream or by insufficient care in making the butter.' We only add the remark that the souring of butter is more frequently caused by negligence in washing out the milk properly than anything else.

This seems the place to mention that a reward of three hundred marks has been offered by the Pharmaceutical Union of Leipzig for the discovery of a sure and practical method for the detection of the adulteration of butter by other fatty substances. The competing descriptions are to be sent in before September 30 of the present year.

Another article in the Journal, by the Rev. Canon Brereton, sets forth the advantages offered by Cavendish College, Cambridge, as bearing on the education of agriculturists. 'The time and the cost,' he says, 'of a three years' residence in College, after the school course is finished, have been considered incompatible with the obligations both of learning and earning, in the business of a farm.' But the reform of schools and the establishment of local examinations have 'not only made the general school preparation itself much more effective for after-life, but have admitted the possibility of adding to the school the further advantage of a college course, and this within the university, and in permanent connection, therefore, with the highest education of the country. In short, many a lad of fifteen or sixteen who has been taught in a good school has it quite in his reach to take a university degree at eighteen or nineteen, and then enter on his professional studies and duties with all the advantages of a completed education. To secure practically this important result, and to offer to such lads the best university instruction, with suitable protection and associates, and at a very moderate cost, the new Cavendish College is now being founded in Cambridge.'

In a recent Month (ante 270) we mentioned an exhaust nozzle for quieting the noise of safety-valves and escape-pipes. This nozzle has since been described in the Journal of the Franklin Institute (Philadelphia). It consists of a spiral coil of wire so compressed as to leave a slight space between the individual turns of the coil. This when properly adjusted is fitted into the end of the escape-pipe: the steam rushes out; but instead of communicating its vibrations to the air, communicates them to the coil. 'As, however, the individual turns of the coil cannot vibrate to any considerable extent without coming in contact with the adjacent ones, interference occurs to such an extent that the vibrations are not transmitted to the air.'

This useful invention (Shaw's Spiral Exhaust Nozzle) has been reported on by a Committee of the Institute, who in concluding their very favourable Report, recommend the grant of a premium and a medal to the inventor, and remark: 'In view of the annoyance, fright, and danger arising from the roar of escaping steam, and of the completeness with which the nozzle destroys this roar, we are of the opinion that Mr Shaw has done a great service to the community, and particularly to the transportation interests, in overcoming an obnoxious and dangerous feature in the use of steam.' The nozzle, we are informed, has already been largely adopted in America. Shall we have long to wait for its introduction here? People who dwell in the neighbourhood of factories and thousands of travellers, are ready to give it a welcome.

Steam-power for tramways instead of horse-power continues to be a subject of experiment, with a view to prevent noise and escape of steam, so that passengers may not be deafened nor horses frightened. It was stated at a meeting of the Institution of Civil Engineers, that the best form of tramway is that which has the rails laid on continuous wooden sleepers, and that there will not be so great a saving as is commonly supposed by using steam instead of horses, for the repairs of the engines will be a heavy item of expense, and the engine-fitters and drivers will require high wages. Some inventors dispense with steam and make use of compressed air; and mention was made of 'a pneumatic car designed by Mr Scott Moncrieff which had been at work on the Yale of Clyde tramways. It carries one hundred cubic feet of air at a pressure of three hundred and fifty pounds on the square inch; and considering that everything about it was of a rough and temporary character, the success obtained was encouraging.' As regards capability, we are told that 'on the level, and on gradients up to one in thirty, engines can do all that is necessary. But the engine has yet to be designed which will stop and start again, with a heavy car behind it, on any steeper inclination without trouble and delay.'

On the other side of the Atlantic, a different conclusion has been arrived at, for, as stated in the Journal of the Franklin Institute, a steam tramway engine has been tried in Baltimore which, with a load of a hundred passengers, can be easily stopped and started on a gradient of seven feet in the hundred, or nearly three hundred and seventy feet per mile. It drew the same load through snow and slush ten inches deep, when four horses were required to draw an ordinary car. This engine weighs sixteen thousand pounds. On suburban roads it travels at from twelve to eighteen miles an hour. Compared with a two-horse car, it shews, in its working expenses, a saving of five hundred and fifty-eight dollars in a year. The power of traction is, however, of less importance than the absence of smoke and of noise from the steam that is employed. Several good specimens of smokeless and noiseless tramway engines have been shewn in this country.

A horseshoe which is described as 'partaking of the moccasin and also of the sandal' has been brought into use at Philadelphia for street traffic, with, as is said, satisfactory results. It is hollow on the under side, and the hollow is filled by a piece of tarred rope, which by deadening concussion, lessens the severity of the horse's labour and the wear of the paving-stones. This shoe is put on cold, and requires not more than six nails to hold it in place. Something has been heard too of a shoe made of compressed sole leather chemically treated, which is lighter and more lasting than iron shoes; but of this we have as yet no particulars. Lightness should be a recommendation; for if a set of shoes weigh two pounds and a horse trots one step every second, he will lift one hundred and twenty pounds in a minute; from which the sum-total of weight lifted in a day's work may be calculated. When farriers and all people who keep horses shall have some real knowledge of a horse's foot, then proper horseshoes may be expected to come into general use.

Mr Outerbridge of Philadelphia has succeeded in producing by precipitation gold-leaf so thin that with a single grain he can cover nearly four feet of surface. Nearly three million of such films would be required to make an inch in thickness. The films are not, as might be supposed, patchy, but are perfectly whole and continuous: they are also transparent, and serve to illustrate the green appearance of gold under transmitted light.

A good example of the economy of fuel effected by the use of compound cylinders is to be seen in Cherry's Compound Steam-pumping Engine, which has been recently exhibited at Birmingham and at Falmouth. With four pounds of coal hourly for each horse-power, this engine, when fixed in a mine, will force water from a depth of more than a thousand feet; and it is of course applicable to overground work as well as underground work. The characteristics, as described in the Report of the Royal Cornwall Polytechnic Society, are 'extreme simplicity, the reduction of friction to a minimum, thorough efficiency of expansion;' and the entire cost of the engine will be less than the cost of the foundations for an ordinary pumping-engine.—With this may be noticed Stevens' patent underground Hauling Engine, which is so compact that it may be placed almost anywhere in a mine, requires no foundation, may be spiked to a piece of timber or wedged to the roof, and is not affected by the moving of the floor, which is not unfrequent in mines. Another advantage is, that it requires but a few hours to get it into working order, and may be driven by steam or compressed air at pleasure.

A common objection to ordinary fireplaces is too much of the heat wasted up the chimney, and various contrivances have been tried to prevent this waste, one of which was an iron plate instead of bars for the bottom of the grate. An improvement on this is Wavish's patent Coal Economiser, which has a hollow-pierced cylinder rising from the middle of the plate. The air entering the cylinder from below the grate is thus conveyed at once into the centre of the fire, and the heat, instead of rushing up the chimney in undue quantity, is diffused into the room, and coal is economised. The perfection of combustion is achieved when, instead of feeding the cylinder with the vitiated air of the room, it is fed by a pipe communicating with the external air. And further, we are informed that 'if a bag of camphor or other disinfectant is hung on the cylinder, the scent is driven into the apartment;' and thus any room in a house may be perfumed, disinfected, or ventilated by this contrivance, when properly fitted.

Among recent patents is one granted to Professor Sir William Thomson for 'improvements in navigational deep-sea soundings.' With this apparatus a sounding can be taken without stopping the progress of the vessel, which is in itself an important advantage. The depth is indicated by appearances in a glass tube, which shew what portion has been occupied by air while under pressure beneath the water. A Frenchman has invented a sounding apparatus which consists of an india-rubber bag filled with mercury communicating with a valved metallic chamber. The pressure of the water forces the mercury into the chamber, and the quantity therein denotes the depth.

Hitherto the electric light, though a brilliant and powerful substitute for sunshine, has resisted the attempts made to bring it into general use. Clockwork has been required to keep the carbon points always the same distance apart, and as carbon wastes by burning, there was too often failure on the part of the wheels. But now Mr Jablochkoff, a Russian military officer, has discovered a way of overcoming the difficulty. His source of light being a magneto-electric machine, strong enough to produce, say, twenty minor lights, he connects the points where these are to be placed with the principal machine by means of wires. At each of those points he fixes an 'electric candle,' composed of two strips of carbon, and a central strip of a fusible and insulating substance described as kaolin. The current flowing from the machine passes up one of the carbon strips of the first candle, appears as a steady light at top, passes down the other strip, and so on to each candle in succession, and returns to the machine from the last of the series. The candles burn about an hour; but as four are fitted to each lamp, and take light one after the other, an uninterrupted illumination of four hours is thus provided for.

This method has been tried with approbation in Paris, and in London at the West India Docks. Gas appeared dull and feeble by contrast, and the onlookers came to the conclusion that by aid of the electric light the loading or unloading of ships could be readily carried on at night. A further advantage is, that the light is portable, and can be taken without danger into the hold of a vessel. Thus by subdividing a single current and leading each division to a 'candle,' it seems that the question of utilising the electric light is likely to be solved.

Mr C. Meldrum, F.R.S., Director of the Observatory at Mauritius, devotes much time to observation and discussion of sun-spots, rainfall, and cyclones. After carefully considering and comparing observations made in all parts of the world, he finds them corroborated by those of his own locality, and that there is a decided and apparently persistent difference between the rainfall of the period of most sun-spots and of fewest sun-spots: the law being, the more spots the more rain. He finds further, that the increase and decrease have recurrent periods, that there are cycles of rainfall, of sun-spots, and of cyclones; and he remarks: 'Although the question has been brought forward simply by way of hypothesis, yet it appears to me that, on the whole, the evidence in favour of a connection between sun-spots, cyclones, and rainfall, is so strong that any doubts or uncertainty that may now exist will soon be dispelled.... The hypothesis does not require that the years of fewest spots must necessarily be years of drought, and those of most spots necessarily years of torrential rains over the whole earth. It merely requires that the rainfall of the globe should be subject to a variation having a period of the same length as the sun-spot period. Observation shews, however, that the years of fewest sun-spots are those in which severe droughts are most to be feared.'

'It would be a hopeless task,' continues Mr Meldrum, 'to try to convince those who judge of the matter only by their sensations, that less rain falls over the globe in some years than in others. Great floods and great droughts, especially floods, make deep impressions on the mind, particularly on the minds of those who may have suffered from them. If in a certain year a man was ruined by a succession of floods, and in another by a succession of droughts, it might be hard to persuade him that, generally, the former was a remarkably dry year, and the latter a remarkably wet one. The opinions of people who trust to their sensations in a question of this kind, are swayed from side to side by every change of weather. It is only by taking annual averages for many places and many years that the truth comes out.'

Papers bearing on this question were read during the past session at the Royal Society, shewing that by careful observation of the periodical phenomena above mentioned, it would be possible to foretell and provide against the calamitous seasons of famine which occur in India. This would indeed be a beneficent application of physical science; but the results of observation are not yet sufficiently definite. General Strachey, F.R.S., read a paper to prove, by a negative process, that 'there has been no sufficient evidence adduced of any periodicity at all.' Thus the question remains open to further observation and argument, of which there will be no lack; but we may anticipate that a profitable direction will be given to both by the new Council appointed by the Treasury to govern the Meteorological Office. This Council comprises the Hydrographer of the Admiralty, and five Fellows of the Royal Society eminently qualified to deal with scientific questions and direct the work of the Office.