work, especially in connection with accurate the wildest ambition of its devotees. In other de- Modern Education. is rather an article of faith than a rational belief; USEFUL AND SCIENTIFIC NOTES. The come discovered by observed at many THE comet Barnard in July does places yet. Professor Millosevich, however, saw it on August 9 from the Observatory of the Collegio Romano, and gives the following position: -R.M.T., Sh. 31m. 56s.; R.A., 16h. 51m. 20 148.; S. Dec., 36, 56′ 25-5'. The comet was very faint. The death is announced of Dr. Burq, at Bièvres, in his sixty-third year. The deceased became well known in connection with a method of cure called metallotherapy, which we described at some length in back volumes. His theories as to the efficacy of copper in preventing cholera attracted some attention, mainly because of the fact that labourers in copper mines, and workers in that metal and brass, are rarely attacked with the disease. From the general spread of a more scientific education, we are warranted in expecting important results. Just as there are some brilliant literary men with an inability, or at least a distaste practically amounting to inability, for scientific ideas, so AT a recent meeting of the Paris Academy of The International Medical Congress, held at there are a few with scientific tastes whose imagina- Sciences, a paper was read on a study of the devia- Copenhagen, was a great success, and the next tions are never touched by merely literary studies. tions of the pendulum at Fort Loreto, Puebla, meeting will be held at Washington in September, To save these from intellectual stagnation during Mexico, by M. Bouquet de la Grye. These obser- 1887. Sir W. Gull delivered a lecture on the several important years of their lives is somevations were conducted by means of a multiplying" International Collective Investigation of thing gained; but the thorough-going advo-seismograph set up in connection with the expedi- Disease," which was really an explanation of the cates of scientific education aim at much more. Their object was to ascertain how far the oscilla- to establish a permanent international committee tion sent out to observe the Transit of Venus. reasons for holding the conference. A resolution To them it appears strange, and almost monstrous, that the tions of the ground and the phenomenon of tides for the collective investigation of disease was dead languages should hold the place they do in general education: may be determined by the vibrations of the peudu- received with acclamation. and it can hardly be denied that their supremacy is lum in volcanic and mountainous regions. the result of routine rather than of argument. I do not, myself, take up the extreme position. I doubt whether an exclusively scientific training would be satisfactory; and where there is plenty of time and a literary aptitude I can believe that Latin and Greek may make a good foundation. But it is useless to discuss the question upon the supposition that the majority of boys attain either to a knowledge of the languages or to an appreciation of the writings of the ancient authors. The contrary is notoriously the truth; and the defenders of the existing system usually take their stand upon the IN the Comptes Rendus for the 28th ult. is a note on the analytical calculating machine invented by Charles Babbage, by General F. L. Menabrea. The author gives a full description of the machine left incompleted by the inventor. He also gives an unpublished letter of Mr. Babbage, dated August 28th, 1843, and certifying that the anonymous English translation of Signor Menabrea's original account of the machine, which appeared, with some brilliant accompanying explanations, in the third volume of the Scientific Memoirs, was by Lady Ada Lovelace, only daughter of Lord Byron. The Earl of Dalhousie, chairman of the Trawling Commission, and Prof. Macintosh, the naturalist, are about to pass two or three days on board an Aberdeen trawler, with the view of making observations which may be useful in connection with the work of the commission. The first "injurious insect" competition in this country was held at Frome last week in connection with a flower show. Miss Ormerod had offered prizes of £3, £2, and £1 for the best collection of food plants injured by insects, with specimens of excellence of its discipline. From this point of view there is something to be said. The laziest boy operation in New York city, and it is said that the description of the insects and of the methods of FOUR large cold storage warehouses are now in the insects themselves, accompanied by a short must exert himself a little in puzzling out a time is not far distant when cold air will be served preventing or remedying their attacks. Only sentence with grammar and dictionary, while in pipes throughout the city, just as gas, water, instruction and supervision are easy to organise and steam are now. One of the novel features of one exhibit, that of Mr. H. Haley, of Frome, and not too costly. But when the case is stated the new Washington Market, now being conwas presented for competition, but that obtained plainly, few will agree that we can afford so structed, is a network of pipes running through the first prize. That there was only one comentirely to disregard results. In after life the the building, through which cold air will be fur-petitor is regrettable, but not a matter for surintellectual energies are usually engrossed with nished to the different meat stands. business, and no further opportunity is found for prise, for, as a rule, agriculturists know very attacking the difficulties which block the gateways A Giraffe Hotel.-Toni Dougan, of Sheepshead little about natural history. Commenting on of knowledge. Mathematics, especially, if not Bay, L. I., has commenced the erection of a gigan- Mr. Haley's method of setting out his specimens, learned young, are likely to remain unlearned. I tic giraffe hotel at that place. The structure will Miss Ormerod says that it conveys all that is will not further insist upon the educational import-be 280ft. in height, and will be built directly over requisite in the way of information as to the ance of mathematics and science, because with the Jerome Hotel, of which Mr. Dougau is the nature of attack, without hampering the inquirer respect to them I shall probably be supposed to be proprietor. Three of the legs will be used as stair-with more labour than just looking at the speci prejudiced. But of modern languages I am ignorant ways and one for an elevator. A large dining mens; and I think that if followed up in agrienough to give value to my advocacy. I believe hall, 40 by 60 feet, will occupy the body of the cultural schools, it would be unfailingly servicethat French and German, if properly taught, wooden animal, while in the neck there wilt be able-both for the above reason, and also that by which I admit they rarely are at present, would go another elevator to the head, where there will be far to replace Latin and Greek from a disciplinary a clam-bake dining saloon. In the eyes two electric fitting a card of one kind of attack after another, point of view, while the actual value of the acquisi- lights will shine forth. This will probably be, according to season or other reason, into the extion would, in the majority of cases, be incompar- when finished, the largest structure of its kind inhibition box, the scholars might thus see what ably greater. In half the time usually devoted, the world. the special injuries then going forward in the without success, to the classical languages, most neighbourhood were caused by; and the method Gas-tight Rubber Tubing.-After several boys could acquire a really serviceable knowledge of years of experiment, Mr. T. Fletcher, of, Warring-of life, and the method of destroying the pest or French and German. History and the serious study ton, has succeeded in making an elastic rubber tube of lessening its ravages, could be readily furnished of English literature, now shamefully neglected, perfectly gas-tight and free from smell. The tube or procured on application." would also find a place in such a scheme. is formed of two layers of rubber with a stratum of thin pure tin between. The inner tube is of the usual grey rubber aud the outer of red; but owing to the difficulties of manufacture the patent gastight tubing can be supplied only in short lengths, eg., 2ft., 3ft., 4ft., and 6ft. Even in those lengths the great advantages of the new tubing will be appreciated by all who have gas furnaces and similar appliances. Brown Stain for Wood. A brown wood An extraordinary yield of wheat is recorded by Mr. Twynam, of Winchester, a single grain having produced 39 ears containing 2,800 grains. The three best ears had respectively 104, 103, and 101 grains. At the Chester Farmers' Club, last Saturday, a paper was read by Mr. Charmley, of Blacon Point, near Chester, on "the sparrow pest," in the course of which the author stated that from observations he had made, he thought he should be quite within bounds in declaring that fully The by small birds alone in the country. Government returns showed that in 1882 3,003,960 acres of wheat were grown, and in 1883, 2,613,162 acres. From these figures he had estimated that if the number of small birds had been reduced by one-half the saving to the country would amount to £770,097. This fact There is one objection often felt to a modernised education, as to which a word may not be without use. Many excellent people are afraid of science as tending towards materialism. That such apprehension should exist is not surprising, for unfortunately there are writers, speaking in the name of science, who have set themselves to foster it. It is true that among scientific men, as in other classes, crude views are to be met with as to the deeper things of Nature; but that the life-long beliefs of Newton, of Faraday, and of Maxwell are inconsistent with stain for the imitation of oak, walnut, and cherrythe scientific habit of mind, is surely a proposition tree wood is obtained by thinning ordinary tincture which I need not pause to refute. It would be easy, the latter according as a lighter or darker shade of one bushel per acre of grain had been destroyed of iodine with alcohol, more or less being added of however, to lay too much stress upon the opinions, of even such distinguished workers as these. Men, brown is desired. The stain should be applied with who devote their lives to investigation, cultivate a a broad brush or a rag. After it has dried the love of truth for its own sake, and endeavour work should be polished.it is, however, possible instinctively to clear up, and not, as is too often the to dispense with ordinary French polish by adding object in business and politics, to obscure a to the stain white shellac. One or other of these difficult question. So far the opinion of a scientific processes of polishing is indispensable to give perworker may have a special value; but I manency to the stain. do not think that he has a claim, superior Moths. For the prevention of moths in furni-alone was worth the attention of all classes of to that of other educated men, to assume the ture and clothes a German paper recommends the the community. On his own farm he was attitude of a prophet. In his heart he knows that use of naphthaline. The powder should be dis- annually put to great expense in protecting his underneath the theories that he constructs there lie tributed over both sides of a sheet of paper to which crops against ravages of birds, and the proporcontradictions which he cannot reconcile. The a sticking medium has been previously applied. higher mysteries of being, if penetrable at all by The powder can be made to adhere to the paper by tion of damage which he had given of one bushel human intellect, require other weapons than those means of pressure. The sheets of paper thus per acre was considerably below the loss he had of calculation and experiment. treated can be inserted between the upholstering sustained year by year. Many of the sparrows Without encroaching upon grounds appertaining material, laid between clothes, or placed about a shot on his farm had been found to contain in to the theologian and the philosopher, the domain room, as may be desired. The German paper does their crops eight, ten, and even twelve grains of of natural science is surely broad enough to satisfy not explain how to powder naphthaline. wheat. He called upon farmers to amalgamate and by all legitin ate means to keep sparrows LETTERS TO THE EDITOR, frequent and remarkable during the first as the down to a proper level. #.0. All Cheques and Post-office Orders to he trade payabis An electrical launch, which has been fitted out [We do not hold ourselves responsible for the opinions of for Mr. J. R. Bridson, of Belle Isle, WinderOur correspondents, The Editor respectfully requests that all mere, by Mr. Banks, of Bolton, was tried lastnications should be drawn up as briefly as possible.] week on the canal between Bolton and Bury. the ENGLISH MECHANIC, 81, Tavistock-street, Covent-garden. All communications should be addressed to the EDITOR o The launch is to be used for keeping up communication between the owner's residence and the main land. The boat is 21ft. long, with a beam of 4ft. Gin., and the motor (a Reckenzaun) is supplied with current by 20 accumulators of h.p. type. The propeller is 12in. in diameter, with 11in. pitch, and makes 450 revolutions per minute. The propeller is to be changed for one of 7in. pitch, when it is expected that a speed of eight miles an hour will be obtained. At the Penston Colliery, Haddingtonshire, they employ pigeons to carry messages between the pits and the offices at Smeaton Park, a distance of six miles and a half. The birds accomplish the journey in from four and a half to seven minutes, whereas telegrams always take an hour or more. The telephone would be an improvement; but, unfortunately, it does not leave a record of the messages. that a have so ** In order to facilitate reference, Correspondents, when much as he knows, but no more; and that not in this TION. second half of the year" (the italics are mine). Mr. Paul appears disposed to refer these strange oscillations of short period to thunderstorms, or cognate disturbances of atmospheric electricity. Be the cause, however, what it may, we are brought face to face with this most important fact, elicited by an eminent American man of science: that the (socalled) Krakatoa barometric waves persistently observed and recorded at Washington many months before the eruption took place, and at a time when the mountain was as quiescent as Trafalgar Square! were not Vinteenth Century, which you gave on page 526, The précis of Professor Mivart's article in the strikingly illustrates the shifts to which the exigencies of dogmatic theology reduce even a man of his brilliant intellectual abilities. Presumably Mr. "Animal Mivart has read Romanes's book on Intelligence"; and if so, and he does dispute the veracity of the narrators whose names are appended to the anecdotes, it seems ALCOHOLIC difficult to conceive that he can deny to the animal BEVERAGES-BAROME-creation both the possession of abstract ideas, and TRIC WAVES OF VERY SHORT also the power of communicating their ideas PERIOD-ANIMAL INTELLIGENCE, generally by a language more or less cognate with that of the human deaf-mute. For example (op. AS BEARING ON EVOLUTION— cit. p. 407), Sir Emerson Tennent tells us how, in COMITES то POLARIS-MELTING riding near Kandy one evening, his party came METALS FOR SPECTRA.-ASTRONO- across a Government elephant carrying a heavy MICAL SIGNS COMPOSITION OF beam of timber across his tusks. On noticing the FOROES-COSMOGONY-THE LATE halt of the party, the elephant raised his head, flung DR. J. W. DRAPER-MOON'S POSI- so as to leave room for the horsemen to pass. Sir down the timber, and backed into the brushwood, Emerson's own horse, however (more equino), shied at the elephant; observing which, the sagacious beast backed and backed, wedging himself in among the trees until the horse could not see him, coming out again, however, and resuming his work the moment the cavalcade was fairly past. I should be a little curious to know upon what psychological principle Professor Mivart would explain this action of the elephant, save on that of its consciousness that the horse was afraid of it; and this being so, the elephant must, without doubt, have had a mental conception of the abstraction fear. So again with what Mr. Jenkins says (p. 402) of the recognition of hardness, sharpness, and weight by the same animal. As for the exercise of an equivalent of speech, the authenticated instances of it by various domestic animals are too numerous for reference; besides, I had (but grieve to say, have recently lost), a dog who talked to me every day of her life, and have yet one who, without her great endowments, both natural and acquired, yet contrives to make and bound with the chains of "the Church" could himself quite intelligible. No one who is not tied shut his eyes to the fact that while human and animal intelligence differ most enormously in degree, yet that in kind they are absolutely one. Electric railways are attracting much attention in the United States, and a number of experimental lines have been laid down. New York, it is suggested, might have both underground and elevated railways worked by electricity. An electrically propelled tramcar is being tried at Cleveland, Ohio; but at present [23192.]-THERE is an article that appeared in its performances are not very encouraging. the National Review for May, 1884, and which has since been reprinted in a pamphlet form, which is emiMajor Marindin, reporting on the Penistone nently well worth reading. It is by Mr. A. J. Mott, accident, declares that it is beyond question and its title is "Alcohol and Total Abstinence." It quickly-acting and powerful con- may be commended to the perusal of all who think tinuous broke ought in this instance to that Eugland is rapidly drinking herself into perreduced the speed that the con- dition, and that the sole way to save her is forthsequences of the accident would probably with to close every brewer's, wine merchant's and have been far less fatal. Major Marindin distiller's place of business, and every publichouse further refers to the brake question as follows :— and beershop in the kingdom. I never remember "The value of a brake having rapid action, and, to have seen the folly and inutility of attempting to make men sober by Act of Parliament more above all, automatic action, in such a case as this thoroughly exposed than it is in Mr. Mott's little can hardly be contested; and although the book. He points out that what has eradicated the Board of Trade has as yet no power to insist vice of drunkenness in the upper classes in this upon the adoption of a continuous brake possess-country is the growth of higher tastes, the increase ing these qualities, yet I would remind the of home comforts, and the attraction of better Manchester, Sheffield, and Lincolnshire Rail-pleasures. Instead," he says, "of being coerced way Company that this is the second emphatic into sobriety by external restraints, their facilities warning which has been given to them within for drinking were never greater than at the present time"; and he goes on to predict that drunkenness the last six months as to the need for automatic will disappear among the lower classes from action in the brakes used upon their line." The identical causes. This is common sense, as opposed first warning, we suppose, was in the report of to the rant of the teetotal platform. Educate the the London-road station accident at Manchester workman, give him a taste for intellectual pleasures, in June, when Major Marindin said "There was and he will assuredly lose, to a greater or less scarcely time for the continuous brake to have extent, his appetite for merely sensual gratification. much effect before the collision, but the train To employ a very immediately available would not have run, as it did, for 75 yards after illustration, it is difficult or impossible to the collision if this non-automatic brake had not conceive an appreciative reader of the ENGLISH been rendered useless by the breaking of the MECHANIC neglecting the perusal of his weekly va uum pipe on the passenger engine when it number on the night of its appearance, in order that he may go and sot in a skittle alley on drugged struck the light engine." Col Rich reporting beer. No one is more sensible than I am of the on the collision at Lime-street station, Liver- terrible curse which drunkenness is to the relatively pool, in July, says that the brake in use on the very small portion of the population who still conL. and N.W. is not a continuous, but a very in- tinue to indulge in it. To say, though, that because different sectional brake. He suggests that the Mr. Sloggers goes home in a maniacal state, from company should encourage their drivers to use beer fortified wth cocculus indicus, and vitriolised the continuous brake for stopping at roadside gin, and executes a war-dance in his hob-nailed boots stations, and take measures to prevent the rule upon the body of the unfortunate creature he lives being broken which forbids its use at terminal with, that hence no workman shall have his pint of ale, or man in another rank of life, his glass of claret or champague, is as though I should be told that because some marine store-dealer had insured £10 worth of stock for £500, and then burnt his house down to defraud the company, that hence I must, perforce, sit through a bitter English winter without a fire in a single one of my grates, save that in the kitchen. stations. Mr. A. Nixon, captain of the London Tricycle Club, has succeeded in riding from Land's End to John o' Groat's in eight days and a half on a tricycle, carrying his luggage with him. tially, to your able (if slightly hypercritical) correPerhaps I may be permitted to explain, deferenspondent, Mr. Sadler (letter 23133, p. 536), that when I spoke of the supposed comites to Polaris in letter 23059 (p. 484), as being "variables of the type of o Ceti," all I intended to convey was that their period of visibility, as in the case referred to, was short in comparison with the time during which they remained invisible. Of course, I quite remember how Mr. Sadler did express his opinion pretty definitely' on the subject of the companions to Polaris. His method was simplicity itself, and was modelled on that of the controversialist who assailed the dicta of Bellarmine. Bellarmine's a liar. So now that we have confuted Bellarmine, we will go on to the next part of the subject!!" I have myself always failed to see any other companions to Polaris than the well-known 95th mag. one; but if-and it is very far from being impossible-this star possesses minute variable comites whose period of visibility is exceedingly short as compared with that of their invisibility, they may well have eluded the greater number of observers. That Mr. S. W. Burnham has failed to perceive any such bodies with his splendid ɓin. The engineering department of University reflector affords, I admit, very strong presumpCollege, Bristol, includes courses of instruction A very remarkable paper by Mr. H. M. Paul, of tion against their existence; and should any for those intending to become civil, mechanical, the United States Naval Observatory at Washing-record exist of his observations with it of Polaris or electric engineers or surveyors or architects. tou, appears in the first number of the American unattended by any other than its familiar comes, The courses arranged for civil engineers, archiMeteorological Journal, published at Detroit, simultaneously with the perception of more by tects, and surveyors are intended to meet the logy must be familiar with the fact that General as practically conclusive as to the imaginary Michigan, U.S. Most people interested in meteoro- some other observer, I should regard his testimony generally acknowledged want of a preparatory Strachey read a paper before the Royal Society, last character of the new companions. Meanwhile, it training for one or two years before the usual December, on the Atmospheric Waves set up by can hardly be said that the question is absolutely entrance as articled pupil into an office. Special the great explosion during the eruption of Krakatoa settled. courses have been arranged for students studying on August 27, 1883. Upon the appearance of for the profession of engineering who wish to in- General Strachey's paper, Mr. Paul applied for perlade in their professional training some know-mission to examine the records of the self-recording logo of electricity and its technical applications, specially with regard to electric lighting and tography, electroplating, &c. The engineering Laboratory has recently been provided with a powerful testing machine, and a practical acquaintance with the use of tools is afforded in the workshop Theoretical and practical courses in surveying are given, and excursions for field practice are frequently made. barometers in use at the Washington Office, a per- In reply to query 51386 (p. 547), I may tell "M.A." that I have myself employed two methods of observing metallic spectra with the Browning'e amateur's star spectroscope belonging to my equatoreal. The first was simply to get a piece of thin loop. Supporting the wire upon one of the small platinum wire, and bend one end of it into a little stands you buy at the operative chemist's shop. I the loop and inserted it in the flame of a spirit lamp fused & bead of the substance to be examined into so holding my spectroscope that the vaporis.nz substance should be very little below the shit of the instrument. On looking through the latter the bright lines are beautifully seen. The worst of it is, though, that they do not last long. A Bunsen's burner gives, of course, a better flame and is, pro tanto, more effective; but I am many miles from any gasworks. My second mode of proceeding is to solder little bits of gold, silver, &c., to the ends of copper wires, and to make them the terminals of my induction coil. The two points of gold, or other metal,fare approximated until the spark passes continuously, and it is then viewed in the spectroscope as before. I have made a piece of apparatus with a common wooden cotton-reel sliding up and down a glass rod, and with my bits of copper wires passing through the rim of the reel both top and bottom so as to bring the corresponding pieces of metal vertically over each other. This assures the verticality of the line of light of the spark, and its coincidence with the properly-adjusted slit of the spectroscope. A Leyden jar in the circuit makes the spark hotter, and the spectra finer and more brilliant. or In reply to query 54419 (p. 570), declination is the original form which the co-ordinate so called took in determining the position of a star. In employing it, however, it is necessary to indicate whether it is north or south of the Equator, and this is done in practice by appending the letter N or S, or the sign + or - to it. Thus we should say that the declination of a Corona was 27° 6' N. or + 27°. 6', and that of Antares 26° 10′ S. 26' 10'. The object of using N.P.D is to get rid of these S. and N, and signs, as North Polar Distances are obviously all reckoned in one direction up to 180°. Taking the two stars just named, we should say that a Corona had 62° 54′ N. P. D., and Antares 116° 10' N. P. D. This is sometimes rather more convenient for calculation. - does mean the difference of longitude between the perihelion and the ascending node of the planet or comet to which it refers, but you must obviously have one of these quantities given, as well, to find the other. Chambers describes all such signs in his "Descriptive Astronomy." In the (impossible) condition of things postulated by" Alpha" in query 54427 (p. 570), his 10lb. weight would go on travelling round and round the surface of the earth for ever, and preserving its initial velocity. I think that Mr. Carwardine (query 54435, p. 570) will find that the Nebular hypothesis of La Place has not yet been superseded as a Cosmogony. There is an account of the life and scientific labours of the late Dr. J. W. Draper, such as Kelby," seems to require (query 54446, p. 570) in the Popular Science Monthly for January, 1874. George" (query 54448, pp. 570 and 571) will find that the Moon will be very approximately on the Equator on the 16th of next October at 3h. 35m. p.m. The sidereal time at mean noon at Greenwich on that day will be 13h. 41m. 388.; and 3h. 35m. minutes afterwards quite obviously 17h. 16m. 38s. But at this instant, the right ascension of the Moon is 10h. 3m. 55s.; which is only another way of saying that the meridian of Greenwich has passed it 7h. 14m. 438., or that it is vertical over some place to that amount West of Greenwich. Turning this into longitude at the rate of 15° for 1 hour, we obtain 108 40' 45'. Now then, let us get our terrestrial globe and stick a tiny disc of paper on the Equator in 108° 40′ 45′′ west longitude, and we shall find the spot in the Pacific Ocean to the west of the Galapagos Islands, over which the Moon will be vertical at our specified date. Having thus obtained our initial point, we can take out the Right Ascension and Declination of the moon for succeeding days or hours, repeating the operation shown above, and calling the latitude graduations on the brass meridian of the globe Declinations, and the longitudes on its Equator Right Ascensions, we can set off her position for any number of successive times, and join their positions on the globe to obtain a visible picture of her path over the earth's surface. A Fellow of the Royal Astronomical Society. COMITES TO POLARIS. (23193.]-I HAD supposed from Mr. Binns's first announcement that he had succeeded in seeing one of M. de Boe's close companions to Polaris; but it would appear from letter 23134, p. 537, that he observed a totally different object. The star having an apparent pos. angle of about 280 in Mr. Binns's diagram is. I suppose, the well-known comes at 213-5: 18.5", and in that case Mr. Binns's star would be at least 35" distant. This is a very different star from either of de Boe's, the brighter of which was supposed to be at 4" distance, and the fainter at 3. We carefully examined Polaris on the evenings of the 11th, 15th, and 16th with the 10in. Calver. The locality being less than four miles south-west of Charing-cross, definition is not always good on stars in that position in the heavens; but I can confidently affirm that on the 16th, at all events, no star brighter than Herschel's 20th magnitude was visible within 90 of Polaris. The annexed rough diagram shows the appearance of Polaris and its companion, and the nearest visible stars at 10 p.m. on the 16th. C is about 18 mag. in H.'s scale, at about 100" or 110 distance, and D 16-17 mag. at about 180" or 190". I may remark that this telescope shows perfectly the close companions of 3 Aquile (O. 2. 532), Delphini (O. 2. 533), 21 Aquila (H. 879), 102 Herculis A. G. C 8), &c.; the comes to Delphini, for instance, being as bright to me as the comes to Polaris is in a 2in. or 24in. refractor. I do not see why the object-glass should not have been slightly out of adjustment, or the eyepiece perhaps tilted in ང ོ the tube, when Mr. Binns saw his supposed companion; the motion of Polaris being very slow the ghost" would shift its position almost insensibly. Anyway, I think this explanation is preferable to any theory of variability, for it is not usual for a star of this character to appear as a 10th magnitude on one night, and to be absolutely invisible twentyfour hours afterwards. If Mr. Binns again suspects the existence of his companion, I should like him to turn his telescope on to Delphini. O. 2. measured a 12 mag. companion (in E.'s scale) to this, and also a distant 9 mag. at 214 7. On the night of the 16th we saw nearly a dozen faint stars nearer than the 9 mag. at 215"; one or two slightly brighter, the others fainter than the close companion, which may be considered a fair test for an Sin. or Sin. object-glass. If Mr. Binns or others who see these companions of Polaris would be good enough to insert the positions of these faint objects on a diagram and publish this at the same time as the observations of the stars near Polaris, they would serve as a useful check on the accuracy of the observations of the latter. Perhaps Mr. Best (who, not content with two or three, sees some ten or twelve companions to Polaris) would favour us with a diagram of the faint stars within a radius of about 3 round x Delphini as seen in his dialyte. Of course, in the case of Polaris, no star having a distance over 60' can properly be called a companion; but the star shown by Mr. Binns is only just over half that distance, and therefore, if it exists, can legitimately be termed so. Aug. 18. H. Sadler. COMITES TO VEGA. in diagram, page 436, are not spurious ones; they [23195.]-I ASSURE Mr. Sadler the stars shown letter 23166, sees with 2in. the 11 mag. comes, I were most undoubtedly seen. If Mr. Holmes, seen no reason why I should not, on nights of extraordinary atmospheric distinctness, see comer of 14 or 15 mag. with 7in. companion star which, on the next night, apparently Burnham remarks that 6in. one night will show a as good, cannot be seen by the largest telescope in the world. E. Miller. My telescope is only a small one (3in.), and being at West Kirby I mentioned the matter to the Rev. T. E. Espin and Mr. Gage. Their telescopen at once confirmed my discovery; and last night, August 20th, Mr. Espin's excellent 5in. achromatic revealed the fact that the 11th mag. comes I had noticed is itself double, and also that there is another comes to a Sagittæ, f., of about the 12th magnitude, and forming with the other companion and its primary an almost equilateral triangle. It is in the hope that others with larger telescopes will observe this interesting and seemingly neglected star, that I venture to ask for this letter a place in your columns. Liverpool. J. H. Honeyburne. P.S. The n.p. quadrant should be carefully scanned. VENUS IN INFERIOR CONJUNCTION. [23197.)-IN letter 23059, p. 484, "F.B.A.S." gave a brief account of a paper published in the Bulletin Astronomique for May, 1884, relative to the crescent of Venus when in inferior conjunction of 1882. Moreover, the latest number of the "E.M." contains some remarks from "F.R.A.S." about my observations in connection with Mr. Ballot's observations (23128), p. 535. In my résumé, I pointed our, without any theoretical explanation, the following features of the crescent: a. The central or surrounding part of the crescent is about 1" broad, in which light seems to be condensed. During the time of observation, Dec. 1 to Dec. 26, it kept all the same breadth, and its inner edge was yet visible at Dec. 26.. 6. The outer envelope, in which fainter light appears to be diffused. c. Near inferior conjunction, the crescent is reduced to the so-called central part. I noticed afterwards the beginning of an inner and much fainter luminous arc, which appears as the true bound of the actual crescent, and I said, calling the attention to the actual crescent, "vient se terminer et se fondre dans les pointes de l'arc interne." a and b are essentially known facts. With respect to c. "F.R.A.S." has suggested for its origin the objective; but my objective (made by MM. Henry) was severely tried by focussing stars and double stars; I do not think there is any satisfactory explanation. Indeed, if you look at Mr. Frauks' sketch, p. 462, and if you admit his statement, the outline of the dark limb certainly belonge to a smaller circle than that of bright limb, p. 462, and (22976), p. 416. There is nothing further sur prising in my observation. Paris, Aug. 20. O. Callandrean. SELENOGRAPHICAL - MAYER-REINMARE IM POLARIS-VEGA. [23194.]-MR. EDWIN HOLMES, letter 23176, p. 560, says: "The comes, as Mr. Binns calls it, south of Polaris, is a very obvious star, but too far distant to call any attention to. It is a little misplaced in his sketch." The italics are mine. He, Mr. Holmes, further says: "It is shown in a sketch I have sent the Editor." These off-hand remarks, coupled with the fact that his observations of the comes to Vega are repeated in both his letters, Nos. 23166 and 23167, would almost warrant the conclusion that he does not, with sufficient care, consider the subject he is writing about, as in this case he is really very wide of the mark. The amusing part of his letter is, to me, that which conveys a doubt as to my capability of delineating the apparent position of three stars. With regard to Mr. Holmes's sketch, p. 560, of 31 stars surrounding Polaris, I have nothing to say, except that the position of the object I and my friends unmistakably (for that is the word in my notebook) east of Mayer. At Sh. 20m. Mayer was invisible, saw on the night of the 6th ult., and described in and by Sh. 50m. the wall began to appear on the my letter 23001, p. 436, can be accurately deter-N.E., but by 9h. 30m. no more could be seen. mined by drawing a fine line from the 8th to the 14th star in Mr. Holmes's sketch, p. 560, and placing on that line a dot, or point, so as to make with Polaris and its companion a right-angled triangle; such dot will then give the exact position of the mysterious object I described in a former letter. It will also be seen that such dot will correspond in proportions, &c., with my sketch on P. 537. Wm. Binns, Assoc. M. Inst.C.E. Lake, Isle of Wight, Aug. 25. P.S.-Looked at Polaris last night with all the powers I before used, including a comet eyepiece, without seeing a ghost of the object, which I should be glad if someone could describe.-W. B. HOLD COPERNICUS BRIUM-PYTHEAS-LAMBERT. [23198.]-IN noticing the peculiarity in the invisibility of Mayer, p. 537, 1 omitted to mention that on Feb. 6 the terminator was on the crater There are several misprints in one of my letters on p. 538, but the only one necessary to correct is that the terminator was W. of Maurolychus when Albateguius was observed. On p. 296, Mr. Gaudibert says that he could not identify the three craters in a row N. of Reinhold, which are shown in Mr. Elger's sketch. On August 13 and 14, when this region was unusually well defined, I saw at least two of them, and another, which I placed rather more east. They pointed to the crater rill which Schmidt shows This rill, which is formed of minute craters, Was beautifully distinct with three larger craters in a triangle on its W. side. Together they form a triangle with Reinhold a and the double crater HOT-AIR CLOSET.-II. [23204.]-SUPPOSING our closet requires power enough to dry for a large family or school, say, 50 persons, we shall want gills enough to form a stove 40in. long. This will heat a closet containing three horses, up to 160°, and this is quite hot enough to work well without damaging any fine articles. A drying closet should always be built on the ground floor; the stove, of whatever construction fixed underneath, as heat in any form has an upward tendency. If, however, there are any difficulties in excavating or connecting to suitable flue, the brickwork chamber may be built outside (see sketch). This is of course dependent upon The mandrel, then, I now submit to the judgment of your readers has an internal cone, into the different positions in each case. The chamber which all the chucks are fitted and secured, as must be about the same length as the stove, shown, by a small steel key passing through both; measured from front to back of gills, the hot-air this key merely holds the cones in contact: and chamber 24in. clear sides and top; the cold air therefore is not calculated to bear any strain: it is supply taken from the back, as shown in sketch of very small taper, so as not to shake loose. There No. 2; the hot-air channel should be as near the are two slots through both bosses; crossing exactly front end as possible, and built into the centre of and at right angles to one another, in the chuck arch, as shown by dotted lines. The brick chamber, boss; but in the mandrel, one is a little in advance if built this way, will require strengthening either of the other, so that if the key be inserted in one by tie-rods or buttresses; the rods are neatest, hole it will draw in the cones; whilst, if inserted in and there is plenty of room for them between the the other, it will separate or release them. Possibly, gills. I have marked the front and back gill plates with so blunt a cone, this precaution will be unwith dots; these should be drilled and tapped to necessary; there is an eccentric chuck shewn in take a small sized rose-head stove screw; the position on the mandrel, and the words "ON," front gill right to the bottom, the back one need"OFF," stamped on the boss to show into which to not be drilled beyond the cold-air grating. Gal- put the key. This chuck, and the cup chuck it vanised netting will do for grating. Two thin carries, are put in to show that the length of the sheet-iron shields are now wanted; 16 B.W.G. cone fittings does not increase the overhang, but will do. These should be large enough to cover rather allows it to be diminished; the cone of the the ends of inner circle of brickwork, and have chuck in the first instance passing down inside the holes punched to correspond with those in plates; mandrel within the headstock, so that in spite of the centres cut out; 2in. of bearing inside the its long solid bearing, the mandrel only projects holes being plenty. The chimney may be carried in., instead of 14in., as in Dr. Edmund's mandrel; any way that is most convenient, the hot-air flue and in the second instance the cup chuck cone a little under the floor of drying room. We must passes through the chuck wheel, and the boss stands now screw on the shields, and see that they fit close out in. only. to the brick arch. A few hooks may be driven in, or, better still, built in, and closed on the shields. The use of thin iron for this purpose allows for expansion and contraction, as it yields readily. There is another stove, an excellent one, made square, of sheet iron, and the furnace built up inside. The air is carried round about the stove by strips of corrugated sheet metal; this also is fixed in a brickwork chamber, the aim being just the same-merely to keep the air as long as possible in contact with a hot surface. I think the principle is made clear enough, and I will, in the next, deal with the drying room. Reference to sketch: A, back gill plate; B, chimney connection; D, hotair chamber; O, hot-air flue; M, outer wall of closet. On Guard. (To be continued.) INTERCHANGEABLE CHUCKS. [23205.]-MUCH as I admire the system advocated with such ability by our friend Dr. Edmunds, I still think the cone fitting the more practical way of obtaining the desired result. I do not doubt but that men like Mr. Hartley might succeed in making chucks interchangeable by means of the cylinder and face fitting; but there are, I think, very few who could do it. With the cone there is but one There being now no screw to interfere, the inside of the mandrel can be rubbed with marking, and the chucks fitted, whether of metal or wood, by hand turning; the fit on which their truth depends being easy to perfect. When the cones are finished, a scriber passed through the slots in mandrel will mark the places for the slots in the chuck bosses. If the key be well fitted, the work may be removed and replaced with no fear of altering its angular position, as by screwing up a little harder on an ordinary mandrel. F. A. M. LATHE MATTERS. [23206.] BOTH Armstrong and "Vulcan" have proposed plans for elevating the headstock, both to turn larger diameters without requiring a gap, and to do milling and drilling without the vertical slide of slide-rest. Now these plans have two disadvantages: they necessitate a special arrangement for the belt, so that it may remain always tight, and that would entail extra friction, and they take the mandrel out of line with the poppet, and this would deprive us of its support when turning a large diameter, and prevent the use of the back centre to steady the milling cutter, which is an important assistance, and would greatly increase its power and steadiness. For these reasons I should much prefer the vertical slide of the rest, and I think it would be easier in that way to secure solidity. "Vulcan" wants to get rid of the noise and vibration of the back gear, and so do I; but I fear the plan he proposes would prove disappointing and feel convinced it cannot be done by a belt, without entailing enormous friction by the heavy pull on the bearings, which would be necessary if the belt is to be tight enough to drive at the slow speed. Our lathe bands drive well enough at present, because they run at a quick speed, and a light pressure suffices; but if you wish to increase the power as 1 to 9, say, as with back gear, and use still the same sized pulleys, you would require a pull 9 times as great, entailing 9 times the pressure on the bearings. The only alternative being to employ a pulley on the mandrel of 9 times the usual diameter, so as to have the belt speed the same as before. A very ingenious differential back gear was published on page 586 of Vol. XXV., patented by Joseph Jewsbury. I have no experience of it, and should much like to see it in action; it should work noiselessly if the wheel teeth are properly shaped (which they are not in the drawing), and perhaps this plan would suit "Vulcan." CONTINUOUS BRAKES. [23207.]-IN one of your recent issues "Nun. Dor." refers to the practical experience of railway engineers with respect to the brake question. It is to a certain extent the test which would enable one to form a judgment of that sort. But what would foreign engineers, who are brought up differently to what the custom is here, think of their English colleagues on witnessing the dogged persistence of railway companies in sticking to valueless brakes? We should like to know on what grounds the directors are still trying to deceive their shareholders as they do. The eyes of the public must be opened and a check put on the proverbial selfishness of English companies. It is not altogether a want of experience, but also personal interests, that lead our railway men to stick to old and dangerous appliances which do no longer correspond to the wants of our immense railway traffic. It is only a few weeks since a terrible accident occurred on one of the most important of our railways, attended by consequences which might have given our railway companies time to reflect. But, no! they are above teaching; and the London and North-Western, railway, after giving up a bad brake, adopts another which has been time after time condemned by the Board of Trade. It is not always out of ignorance that railway chairmen speak as they do. They try to dissemble their fears of being compelled to do what they have so obstinately refused to do. They are not afraid of fallacies to support their dicta against a brake whose introduction has already been so beneficial. Engineers are partly responsible for this state of things, and I think very little of a man who, being only practical, will not hear of theory; for many of those French engineers who induced their companies to adopt the Westinghouse brake are not the sort who would be liked in England: they are better educated than their English brethren. Most of them have never served their time in the workshop, and yet engineering science owes them much. All that has been done to settle this brake question was done by men possessed of higher scientific attainments than those of the engineer who was trained up in the old fashion. Such a training as most future engineers receive in England has its good sides; but, if it is necessary, it is also insufficient. But what is, after all, the |