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London Entomological and Natural History Society, 1914-15. Original observations, made by the author himself, add materially to the value of this contribution. Originally, it is assumed, developed as a protective device against enemies the light-emitting qualities being associated with, or perhaps the cause of, nauseating properties-luminosity has become primarily a secondary sexual character. This much is attested by the response which can be obtained by experiment from the use of small electric bulbs. These experiments conclusively show that each species has its own characteristic method of exhibiting its light, and that an individual from any one species will, as a rule, only respond to, or evoke an answering flash from, a member of the opposite sex of that species. Some species, moreover, respond more readily to artificial flashes than others. Some will answer the flash of a match. Luminosity in some cases, however, seems to play a directly utilitarian part, as in the case of the fly Thyreophora cynophila, which is said to be nocturnal in habit, and to feed on dead bodies by the light of its phosphorescent head. Finally, the author discusses numerous instances of pathological luminosity due to luminous bacteria, as in the cases of certain midges and crustacea.

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STUDENTS of genetics, no less than systematists, will welcome the "Review of the South American Sciuridae," by Mr. J. A. Allen, which appears in the Bulletin of the American Museum of Natural History, vol. xxxiv., 1915. In discussing the value of size as a 'group character," the author remarks that closely related forms present a small average range of variation, inter se, and a very wide range of individual variation. Specificity is determined, not by individuals, but by groups of individuals. In attempting to discover tangible differences in the form of the skull and the character of the teeth in American squirrels, with a view to their use as the basis of generic or subgeneric divisions, some surprises were met with in respect to the variability of such features in specimens of the same species from the same locality. The form and the details of the crown pattern of the last premolar and the last molar were found to be extremely unstable features. The author also makes some extremely interesting observations on colour variations and the evolution of new types of coloration.

FROM the Department of Agriculture, Ceylon, have been received Bulletins Nos. 12, 13, and 14, dealing with Hevea tapping results at the experiment station, Peradeniya, the tapping of an old Hevea tree at Heneratgoda, and manuring of cacao at Peradeniya respectively. The old Hevea tree is apparently one of the original trees sent out from Kew in 1876, and its girth in August last was 117 in. at 3 feet from the ground. The tree has been tapped with short intervals over a period of 4 years 9 months, and the total yield

of rubber has been 392 lb. 7 oz.

THE Polyporaceae of Wisconsin form the subject of Bulletin xxxiii. of the Wisconsin Geological and Natural History Survey. This great family of fungi, which has been worked out by Mr. J. T. Neuman, is represented in Wisconsin by a great number of species,

and Cyclomyces is the only genus unrecorded. Tir bulletin consists of 148 pages of descriptive text wit twenty-five plates of figures, which should enable the fungi to be easily identified. As many of the Poly poraceæ are serious timber-destroying fungi the book should prove of value in the United States. Of the destructive forms, Polyporus abietinus, P. pergamenus growing on maple, willow, oak, etc., Trametes pin and Fomes ungulatus, cause the greatest damage to timber trees.


WE have received a copy of a new publication entitled "Egyptian Agricultural Products," published by the Ministry of Agriculture, Egypt, dealing with Sorghum vulgare, Pers., the great millet and its varieties, and also with S. halepense, Pers. account, No. IA, 1915, has been compiled by Mr. G. C. Dudgeon, consulting agriculturist to the Ministry of Agriculture, Egypt. Botanical descriptions of the types and the varieties are given, followed by details of the history of the great millet in Egypt, and full cultural details. It seems probable that S. halepense, which is indigenous in Egypt, is the plant from which S. vulgare and its numerous varieties have been evolved. The uses of the grain and the leaves are also dealt with, and the question of the poisonous character of the young leaves is discussed. When grown under dry conditions the young leaves appear to be more poisonous than when grown moist, but as the toxic properties are destroyed by heat the precaution is always taken of exposing young leaves to the sun for some time before feeding them to cattle. When mature the leaves afford a safe cattle food.

THE first volume of the Agricultural Statistics of India (1912-13) is particularly valuable on account of the new features, which include charts, summary tables, and a comprehensive introductory report. The charts indicate considerable progress since 1901, and the increased acreage devoted to cultivation has been accompanied by an improved yield in the crops. The decline in the acreage devoted to indigo and opium continues; and the minor fluctuations in area under the other crops are shown to be largely due to rainfall deficiencies. In a comparative statement it is shown that India has under rice more than eleven times the | area of the paddy fields of Japan, that India is the third country in the world in regard to acreage under wheat, since there is under that cereal three times the Canadian area and three-fifths that of the United States, that India has the largest acreage under maize outside the United States, and that the area under cotton in India is three-fifths that of the United States and twelve times that of Egypt. This issue may be regarded as the first of a new series of annual reports.

AN important contribution to the geography of Canada has been made by Mr. J. B. Tyrrell, of the Geological Survey, in a paper reprinted from the

Transactions of the Royal Canadian Institute, Toronto, entitled "Algonquian Indian Names of Places in Northern Canada." In the course of fifteen years' service in that region Mr. Tyrrell made extensive inquiries from natives regarding the original names of the chief physical features in the Cree and Ojibway

languages. He gives a long list of the native names with those now current. In some cases the native name has been preserved with more or less modification; in others it has been replaced by a translation into English; in others, again, it has been replaced by a purely English designation. Thus a place which in the native tongue was called by a name meaning "A Hole through the Earth," has become "Oxford Lake." The native terms now recorded throw welcome light on the proper pronunciation of geographical terms. It is to be hoped that these names will now be systematically recorded before they finally disappear. Such lists may supply some information on Indian tribal history before the entry of Europeans into the country.

ALTHOUGH the genesis of the various thirty-two systems of crystallography has formed the subject of numerous writings at the hands of Hauy, Brocke, Bravais, Schoenfliess, and others, a suggestive note contributed to the Atti dei Lincei, xxiv., 7, by Dr. C. Viola throws new light on several portions of the subject. Instead of basing his classification on symmetry, he classifies the principal six systems by means of the properties of zones normal to faces, proving the following theorems :-A plane of symmetry is a face and is normal to a zone; an axis of symmetry is a zone, and is normal to a face; a zone which is normal to a face is necessary for the existence of a plane of symmetry or of a symmetrical or specular axis; two zones normal to faces and inclined to each other involve the presence of a zone orthogonal to them, and as many zones normal to faces as there can be in their common plane; two orthogonal zones normal to faces involve the existence of a third, and only a third, zone normal to a face; three zones normal to faces inclined to each other are sufficient and necessary conditions that every face should be normal to a zone. These theorems establish the existence of the following systems: triclinic, monoclinic, trimetric, dimetric, hexagonal, and monometric. It is pointed out that similar methods are applicable to investigate the properties of systems other than crystals.

MR. W. THOMSON described to the Manchester and Salford Sanitary Association on July 6 an ingenious method for obtaining a dust and smoke record. A hollow brass cylinder has a small slit cut in the side over which a ribbon of filter paper is stretched, whilst the air is passed through the paper by exhausting the interior of the cylinder. After a half-hour's exposure the ribbon is automatically moved on and a fresh surface exposed. In this way the fine dust and smoke are deposited in rectangular patches at half-hour intervals, and the depth of colour produced can be used as a means of comparison over any desired period. It appears that in Manchester, where the investigation was carried out, the atmosphere is most polluted on Mondays and Tuesdays and least on Sundays.

PART 3, vol. v., of the Journal of the College, of Agriculture, Tokyo, is almost entirely devoted to mycological researches, and it forms a very important addition to the literature on the subject. With one exception the papers are printed in English, and it is to be hoped that one desirable result of the present disastrous war

will be the spread of English in preference to German in the scientific literature of Japan. The papers are illustrated with plates of great accuracy and beauty, which testify to the care with which the investigations have been performed. Indeed, they would appear to rank with those carried out in the famous Carlsberg Laboratory of Copenhagen. It is interesting to note the developments caused by the intrusion of chemistry into mycology-the Saccharomyces are characterised to-day as much by their selective behaviour towards various carbohydrates and amino-compounds as by their morphological characters.

FERMENTED beverages have always been the huntingground of the mycologist, and the majority of the known species have been obtained from this source. The beverages of the Far East are quite peculiar in the nature of their ingredients, and experience has demonstrated that they contain a unique flora of Saccharomyces. The latest Chinese beverage to be studied is "Shaoshing-chu," of which very large quantities are manufactured in the province of Chü-Chiang. Mr. Takahashi describes (Journal of the College of Agriculture, Tokyo, vol. v., p. 200) several varieties of Saccharomyces shaoshing, a new species of yeast analogous to saké yeast, as well as four new forms of a Zygosaccharomyces shaoshing. The same number of the journal describes the budding fungi of a beverage made from a mash of steamed soy bean and roasted wheat. Five different Zygosaccharomyces were isolated. The assimilation of amino-acids from their pabulum by these yeasts is studied in detail, and the interesting fact established that it is materially smaller than in the case of saké yeast. . Another Japanese beverage of which the soy bean forms the basis is "Hatsuchō-miso." This generally takes from three

to five years to ripen, and is highly valued on account of its special aroma and taste. A preliminary investigation of the fungi present and the chemical changes occurring during the ripening indicates that the quantity of amino-acids present in the mash is an important factor, and there is a probability that such work will lead to the improvement of the product.


A BRIGHT METEOR, JULY 17.-A brilliant, swift meteor (Venus) was observed by Mr. H. E. Goodson at the Hill Observatory, Salcombe Regis, on July 17, Ioh. 54m. p.m. G.M.T. The path practically crossed

Scorpionis, and was directed towards 42 Librae. The trail, about 3° long, persisted several seconds.

THE DETERMINATION OF EASTER DAY.-Anyone who desires a clear and simple account of the principles on which the determination of Easter Day depends may be recommended to consult a paper by Dr. A. M. W. Downing, which was read before the Victoria Institute on March 15 of this year. The problem involves the combination of the three incommensurable periods, the week, the lunar month, and the tropical year, and has been further complicated by changes in the calendar. The way in which the adjustment has been effected to comply with the primitive ecclesiastical rule is here explained in untechnical language and with much interesting historical detail. A discussion of the more comprehensive mathematical rules, like that of Gauss, would have been outside the scope of the paper, which deals rather with the construction and use of

the Prayer Book tables. Some account is also given of the Jewish calendar, with some reference to the astronomical evidence bearing on the date of the Crucifixion. The paper was followed by a discussion, which is reproduced with it.

Dr. Downing expresses himself in favour of making Easter Day a Sunday in a fixed week, remarking that the lengthy explanations required by the present system make a strong argument in favour of this course. But, as he admits, no change is feasible which does not carry with it universal agreement. It is a little difficult to appreciate the opposition to a fixed Easter, which found expression in the discussion following the paper. The association of ecclesiastical festivals with certain astronomical conjunctions is intelligible, even if it fails to carry sympathy. But this is precisely what the present artificial rules do not secure, a fact illustrated in the year 1905, alluded to by Dr. Downing, when Easter Day fell four weeks later than it should have done according to the real moon, and also by the complete variance between the Eastern and the Western churches. The opposition between religious sentiment and practical convenience would probably change in form if, instead of suggesting a fixed Easter, it were proposed to fix the dates of all public holidays, and so to dissociate them from all religious observ


CEPHEID-GEMINID VARIABILITY.-In the Astrophysical Journal (vol. xli., No 4, pp. 307-14) Mr. C. D. Perrine brings forward a tentative explanation of this type of stellar variability based on an inquiry into their orbital characteristics, etc. Discussion of data regarding thirteen stars indicates that the conditions requisite for the production of such variables are large eccentricity combined with small distance between components and small mass of secondary. The few cases of F- and G-type stars other than the variables in question with similar masses of secondaries and orbital dimensions have small eccentricities and show no variation in brightness. It is therefore suggested that the variation of light is caused chiefly by changes in the light of the secondary due to disturbance in the part of its orbit near periastron, the maximum of light occurring at about the time of maximum approach of the primary.

VARIABLE STARS.-A series of notes and data dealing with various subjects related to stellar variability is contributed by Dr. Harlow Shapley to the Astrophysical Journal (vol. xli., No. 4, pp. 291-306). Some of the observational work was carried out at the Princeton University Observatory, but the material was worked up at Mount Wilson. Using the bolometric observations of the Astrophysical Observatory of the Smithsonian Institution, Dr. Shapley has been able to investigate the darkening towards the limb of the sun in comparison with the similar darkening revealed by the study of eclipsing binaries. It has now been found that, although the empirical formula adopted at Princeton in the case of eclipse variables does not completely represent the solar darkening, the agreement is nevertheless quite close, the error being generally less than 1 per cent. It is also found that the darkening coefficient varies with the number of sun-spots, more especially for light of shorter wavelengths; a variable darkening coefficient is thus suggested. Another note contains some interesting conclusions regarding the periods and spectra of close binary stars. The data employed by Wicksell in a similar investigation has been legitimately extended by the inclusion of eclipsing variables. Cepheid variables were, however, eliminated, Dr. Shapley having come to the conclusion that they are not binary systems (see NATURE, vol. xciv., p. 572). Thus modified, the data does not show the secondary maxima of period found by Wicksell, except in the case of B-type stars.

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The maximum number of periods are between 2-5 and 6 days. Other notes deal with variable stars U Pegasi, o Persei, R. Canis Major, and AE Cygni, and the number of naked-eye variables.

THE SOCIETY OF CHEMICAL INDUSTRY. THE Manchester meeting of the Society of Chemical Industry on July 14-16 was by far the most important gathering of chemists since the commencement of the war, and its success augurs well for the future of the society. Hitherto the annual meetings have been largely of a social character, and though they have served a valuable purpose in promoting personal friendships, it has been widely felt that the society has not taken full advantage of the opportuni ties for the discussion of industrial problems which the annual meetings provided. It was obvious this year that social functions were entirely out of place, and the organising committee devoted their efforts to securing discussions of matters of prime importance to British chemical industry.

At all the sittings, and still more in the general conversations, there was a consensus of opinion that the time had come for the society as a body to take active action in regard to these matters. The gathering was a representative one, and was largely attended by the industrial chemists of the Manchester and Liverpool districts, and also by those further afield, in spite of the calls on their time made by war work. The academic element was very well represented, a noticeable feature being the presence of many of the professors recently appointed to act in a consultative capacity to the national dye scheme. Although visits to chemical works did not form part of the official programme, there was marked evidence on the part of manufacturers to oblige in this respect, showing that the need of greater co-operation amongst our chemical industries to meet foreign competition was not overlooked.

The themes underlying all the papers, as well as Prof. G. G. Henderson's presidential address, were the same the need of closer co-operation between the manufacturer and the chemist, and the necessity of improving the training, not so much of the would-be chemist, as that of the managing classes of the community so as to bring about a better appreciation of what science and scientific method really are, and how they can be turned to practical account. important is the necessity of organising industrial chemists as a whole, so that they can speak authoritatively and with a certainty of being heard in the

counsels of the nation.

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The discussions were to the point, and were brief. largely because the meeting was in entire agreement with the suggestions before it. A greater public participation in them by the representatives of industry might have produced new facts and suggestions, and the president should have made a more direct appeal on these grounds. Judging from what was said in private, the view-point of the man engaged in industry is imperfectly appreciated by the professor, and as the latter is more generally heard on the public platform, there is a danger of the practical side of the issues being insufficiently represented. This is particularly the case in regard to the many committees appointed in connection with the war, on which the chemical manufacturer is very inadequately represented.

Prof. Henderson, in his presidential address. considered that the comparative failure of chemical indus try in this country was due to the lack of appreciation of research, to the absence of co-ordination between manufacturers and professors of chemistry, and especially to the lack of provision for enabling men of academic training to apply their knowledge to indus

IN 1914-15.

ANY review of the work of the National Physical
prefaced by a tribute to the ready response with which
Laboratory during the year 1914-15 should be
the staff greeted the call to the colours at the outbreak
of war. In the annual report of the laboratory, pre-
sented on June 15, at the Royal Society, to the General
Board, attention is directed to the consequent marked
reduction in the staff and its effect upon the
distribution of duties. Many who were prepared to
volunteer had to be retained by reason of stress of
war work. Some 25 per cent. of the total staff were
spared for service.

try. This last is undoubtedly one of the greatest difficulties, and to meet it he advocated a scheme of industrial fellowships on the lines of that introduced in America by the late Prof. Kennedy Duncan. A discussion on this point would have been illuminating, as there is no doubt that in the opinion of the manufacturer much of the product of the modern university training is disappointing. The excessive devotion to physical and theoretical chemistry, an insufficient knowledge of general chemistry, poor manipulative power, and lack of ability to tackle even simple problems are the common defects in their training, and if, as is usually the case, these manifest themselves after the newcomer has been taken into the confidence of the firm, the result is to shake the confidence of manufacturers in the university chemist. The ability of the chemist to take charge of a process is a natural rather than an acquired gift, but it is essential if the works chemist is to make material progress in the scale of promotion, as it is only the largest firms which can afford to maintain a large staff of highly-points out, however, that an enforced economy may paid research chemists.

Dr. M. O. Forster also emphasised the chasm between the college and the factory as responsible for much mischief, and would appear to put the blame largely on the factory. It is a pity that a further paper on this subject was not secured from a responsible person in one of our largest chemical works, as there is a strong counter-feeling prevalent that the college and the scientific societies, by holding aloof from the factory, tend to place industrial chemists on a lower plane in the profession, and debar the most gifted students from entering the factory.


An address by Prof. H. E. Armstrong dealt with the need of organisation within industry for the purposes of development and the protection of the interests of industrial chemists. He emphasised particularly that chemistry had not attracted the right stamp of man-one of generous mind, good presence, and real ability-in sufficient numbers. They looked to the older universities, particularly to Oxford, to supply this type, whereas the universities, owing to their neglect of the science schools, encouraged their graduates to take up law, mathematics, or classics. Such material would be worth, and would command, good pay when properly trained. The desire for a scientific vocation must begin in the schools, and schoolmasters must encourage their best pupils to this end instead of advocating classics, because the immediate prospect of scholarships at the university was greater. The success of German chemical industry is due to two causes; first, the fact that their universities are practical insitutions properly supported by the State, and in touch with the educated community; and, secondly, the factories are in the hands of experts. The development has been from within, though it has received great assistance from public sources. The academic party has worked under conditions of freedom, of Lehrfreiheit and Lehrnfreiheit, whereas in England the tradition that it is necessary to be well-read instead of wellpractised has prevailed.

Dr. Beilby, in a paper on chemical engineering, distinguished between the engineer proper and the chemical engineer, rather to the detriment of the latter, though he does not overlook the fact that, if the engineer is not in full sympathy with chemical problems, and acquainted with the action of chemical substances on his materials, his plant will be a failure. The chemical works engineer is called a more adaptable but a rougher type of man, though it is afterwards admitted that he is "born, not made." It is the possession of large numbers of highly, specially trained chemists and engineers which gives the German chemical works its commanding position.

Dealing with matters of finance, a recovery in receipts since September and the maintenance of a stringent economy throughout contributed to a year's total which was not so unsatisfactory as had been apprehended during the earlier stages of the war. The report

well, if too long continued, prove disastrous. Special mention must be made of the generosity of the Hon. Sir C. A. Parsons, in placing a sum of 1000l. at the disposal of the committee; this enabled some serious gaps in equipment to be filled. Steps were taken in July, 1914, to proceed with a recommendation of Lord Parker's Committee on Research in Telegraphy and Telephony, on which the director of the laboratory, Dr. Glazebrook, was serving. It was proposed to establish at Teddington a National Telegraphic Research Laboratory. Since the outbreak of war, however, the matter has been in abeyance.

With regard to test work it may be said, in brief, that the war conduced to a shrinkage in aggregate, but, at the same time, to a large increase in some directions, notably in the electrotechnics and the optics divisions. International work of all kinds has practically come to a standstill. It should further be emphasised, before touching more specifically on the progress of the laboratory during the year, that the research work had, by force of the abnormal conditions prevailing, to be diverted in a large measure to abnormal channels.

A full list of papers published by, or communicated from, the laboratory during the last two years will be found in the report. The twelfth volume of " Collected Researches" is shortly to be issued.

To pass to a few details of the report, mention should in the first place be made of a series of inter-comparisons made during July last in collaboration with two visitors from the PhysikalischTechnische Reichsanstalt, Dr. Giebe and Dr. Scultze, between laboratory standards of resistance and inductance and some coils the absolute value of which had been determined previously at Charlottenburg. Further international measurements may also be noted. In Japan, differences of the order 8 parts in 1,000,000 were found between five mercury' resistance standards, which had been constructed at the laboratory, and five tubes calibrated at Tokyo; whilst four Weston cells brought from Petrograd to Teddington agreed with. the mean laboratory standard to within part in 100,000. Inter alia, an important investigation of the irregularities commonly observed in the Weston normal cell was brought to a close during the year. An interesting series of experiments was also carried out in connection with the measurement of highfrequency currents. With suitably designed air- or iron-cored transformers it was found possible to measure, with precision, currents ranging from 1 to 50 amperes at frequencies from 50,000 to 2,000,000 ~ per sec.

Two valuable photometric papers claim attention. These deal with the unit of candle-power in white

light, as held in electric substandard lamps, and with the estimation of high temperatures by a method of colour identity. Reference may here also be made to the first report issued by the Committee on the Lighting of Factories and Workshops, of which the director of the laboratory is chairman. In the direct-current division good advance is reported with the research on the heating of buried cables.

With the co-operation of Dr. Schultze, two standard resistance thermometers, the constants of which had been studied at the Reichsanstalt, were re-examined at the laboratory. Owing to the war, no official comparison of the Reichsanstalt and the laboratory figures has been possible; but the two sets are known to be in close agreement. In a revision of the high-range mercury standard thermometers valuable assistance was given by Dr. René Paresce, of the Bureau des Poids et Mesures. The heat division was also occupied with research on refractory materials and on heat loss from surfaces.

In the metrology division the silica standard metre was kept under close observation, and it is promising to hear that no measurable extension could be detected during the year. Other items of interest are a series of rulings, undertaken for Prof. W. H. Bragg, to illustrate his work on X-ray spectra, and a report issued to the Board of Trade on leather-measuring

machines and templates.

In spite of the absence of Dr. Kaye on active service, the radium division flourished during the year. Samples amounting to the value, 35,000l., were submitted for test; up to March, 1914, the corresponding figure was 300ol. The division promises to thrive.

Not more than a broad selection can here be made from the numerous investigations of the engineering department. These range from experiments on the resistance of materials to alternating shear and combined stresses to an examination of cracks in the Tower of London. Considerable progress was made with a research on the methods of notched-bar impact testing, which is mainly concerned with a determination of the correct relation between the mass of the hammer, the velocity of striking, and the linear dimensions of the specimen, in order that tests on similar specimens on different scales may yield consistent results. Attention may also be directed to a report on power transmission through motor gear-boxes. On varying the quantity and the viscosity of the oil in such boxes, surprising alterations in efficiency were observed. Passing to the aeronautical division, the new 7-ft. wind channel is now in full working order. The researches of this division on the longitudinal and lateral stability of aeroplanes are well known, and call for no review here.

Interesting profiles of road surfaces at various stages in test were obtained by the Road Board laboratory, and numerous road materials examined under the microscope and otherwise.

Of the work accomplished during the year by the department of metallurgy, it must suffice to instance important researches on the constitution of aluminiumzinc-copper and copper-tin alloys, and an investigation of a new reagent for etching steel. Mention should also be made of some tests carried out by the chemical division on optical glasses, and of a report issued to the Board of Trade giving the results of an investigation into the precautions necessary in the transport of barium peroxide at sea. Some serious fires at sea, notably that on the Volturno in October, 1913, have been attributed to the spontaneous ignition of cargoes of this substance. Results of great interest will be looked for from the newly-erected rolling mill. Compared with last year's abnormal figure, the number of models for private firms tested this year in the National Tank proves somewhat moderate. By

suitable form modification, reductions of power at service speed, ranging to 13 per cent., were secured Various researches were either continued or completed. In conjunction with that relating to fulness of form and longitudinal distribution, special study was made of the wave systems formed by the models. Further. more, attention was directed to the question of the similarity law suitable for strut-resistance. Unless suitably corrected, the resistance of a full-scale strut may, on the basis of measurements on a model, prote enormously over-estimated.

That for a brief review numerous items of interest must pass unmentioned is inevitable. Sufficient, however, has been said to testify to the energy and success with which the work continues to be carried on despite adverse circumstances. It is to be hoped that, during the present emergency, every advantage will be taken of facilities which the laboratory can offer. Perfection and efficiency in all supplies of instruments and technical apparatus, with expedition in dealing with special questions, spell success to those fighting on sea and land.



MR. D. D. KIMBALL, the president of the American Society and Heating Ventilating Engineers, and a member of the New York State Commission on Ventilation, has sent us two papers, one on the heating and ventilation of school buildings, and the other on church ventilation. He says that most of the failures of the past may be justly attributed to insufficient appropriations for the installation of ventilating systems and for their maintenance and operation. Very many installations are incomplete, ill-designed, and installed with the use of unsuitable and cheap apparatus. Possibly the most frequent and serious cause of failure is the want of proper skill in operation. Plants are operated by boys or janitors who know absolutely nothing of the rudiments of fuel-burning, or care of a steam plant, or of a ventilating system. Often, too, there are such restrictions applied by the authorities that the proper operation of the plant is impossible. A school board, for example, directs that the plant must not be operated before or after certain dates, regardless of outside weather conditions, or offers a bonus to the janitor for saving coal, and yet directs that he must always operate his fan engines. He removes the belt between engine and fan, and so secures his bonus.

Mr. Kimball rightly insists on the heating and ventilation of schools being considered of the first importance in the estimates of any public building. Far too much is thought of the external appearance. The architecture should be adapted to the perfection of the physiological needs of the occupants, and the heating and ventilating engineers should be of equal authority with, not subservient to, the architect. A plan is given of the Wm. H. McKelvey School, of Pittsburgh. The air is taken through windows into a fresh-air chamber, from which it passes through tempering heaters, air-washers, and reheaters into a double plenum chamber. From there it is driven by a motor fan into ducts with connections from the upper, or hot air, chamber and the lower, or tempered air, chamber. An individual duct runs to the base of each vertical flue communicating with the class-rooms. The mixing and volume dampers for each room are placed in the plenum chamber, under control of the janitor.

The chief advantage of this system is that the required volume and temperature demanded by each individual room may be had. Two sides of a building

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