250 



KNOWLEDGE. 



[November 1, 1898. 



arts, a3 far as literary presentation is concerned, are 

 extremely difficult to communicate, and glass blowing is 

 an art of that class ; it is, nevertheless, an art of the 

 highest importance to scientific students — more particularly 

 research students — and yet not more than about one in a 

 hundred becomes really proficient in this auxiliary handi- 

 craft in the chemical and physical laboratory, while only 

 a very moderate percentage attain tolerable dexterity. 

 Glass working at the lamp, we take it, is, as Mr. Bolas 

 says in the handy treatise before us, " specially calculated 

 to lead to an intelligent study of the reasons for and 

 agamst various modes of manipulation, and to an appre- 

 ciation of the importance of economy in eifort. . . 

 To surgical and dental students, as also all students of the 

 more delicate handicrafts, a preUminary training in glass 

 working should be specially useful, especially from the 

 point of view of early acquiring ambidexterity." Practical 

 wor'b>,in all the sciences rests ultimately on accurate 

 mechanical operations; aod however ingenious one may be 

 in origmal suggestion, he must also be able to execute the 

 needful manipulative work, or somebody must do it for him. 

 That Mr. B jlas is fully conscious of the magnitude of the 

 task he has undertaken may be gathered from a passage on 

 page 10, where he says : " Tue harmony of action between the 

 two hands of an expert glass worker is probably beyond every- 

 thing in technology ; as, for exiimple, when a longish tube, 

 unequal in diameter at the two ends, is softened in the 

 middle and then operated on, say by blowing in at one end. 

 ISot only must the two hands rotate the piece at the same 

 angular rate while before the blowpipe, but each half must 

 be balanced on the hands. When taken from the flime 

 for blowing, the rotation must be maintained, and both 

 hands must move in such exact correspondence as to put 

 no unintentional strain on the soft part." All through the 

 book the author thus indicates difficulties in every detail 

 of the art and suggests means of overcoming them. It is, 

 therefore, very gratifying to come across a work sufficiently 

 practical to make not only a laboratory and workshop guide 

 to the various phases of glass working at the blowpipe, but 

 also, to some extent, technically educational in the real 

 sense of the term—" as leading towards an understanding 

 why each particular operation is done, and as facilitating 

 that interdrift of method from craft to craft which is so 

 conducive to progress." Those who desire to acquire 

 artistic skill in the use of the blowpipe as a modelling 

 tool — a tool acting with equal facility for relief or intaglio 

 — will find ample suggestions in this book, suggestions and 

 instructions which will enable them to model figures, faces, 

 and expressions, as Venetian artists did in days gone by. 



THE NEW PLANET DQ. 



By A. C. D. Ckommelin. 



IF one were asked to name the optical discoveries which 

 have marked epochs in the history of our knowledge 

 of the solar system, one would probably enumerate, 

 among others, the discovery of Jupiter's satellites, 

 of Saturn's ring, of Uranus, of Ceres and her com- 

 panions, and of Neptune. The discovery that has now to 

 be chronicled may claim to rank in interest and importance 

 at least as high as that of Ceres, for it has peopled a 

 region of the solar system which has hitherto been regarded 

 as absolutely blank, and has provided our earth with a 

 neighbour wliose least distance is only half that of any 

 other heavenly body except the moon. 



The discovery of minor planets has advanced so rapidly 

 in recent years that a new one is greeted with but a 

 moderate degree of interest. But the telegram announcing 



the discovery, on August 13th, by Herr Witt, of the Urania 

 Observatory, Berlin, of a new planet, provisionally desig- 

 nated DQ, was seen at once to have in it somethin ? unusual, 

 for the planet was retrograding at the unprecedented rate 

 of half a degree per day, whence it was evident that its 

 orbit must differ in a marked manner from those of the 

 other minor planets. The planet was accordingly carefully 

 followed by a large number of observers during August, 

 and at the beginning of September Dr. Berberich, of 

 Berlin, set to work to determine, as accurately as possible, 

 the orbit of the new body, using for this purpose three 

 observations made by the discoverer on August 14th, 

 23rd, and 31st. The elements that he deduced are as 

 follows : — 



Aphelion passage 1898, June 20(L'4i3 Berlin mean 



time. 



Longitude of perihelion ... 122° 17' 14" 



Longitude of ascending node 303 48 53 



Inclination to ecliptic ... 11 6 57 



Eccentricity 022865 



Mean distance from the sun 1' 46061 The earth's mean dis- 



Least „ „ „ 11260 J- tance from the sun 



Greatest ,, „ „ l'794fij being unity. 



Average daily motion ... 2010"' 131 



Period = 664-734 days = 1 year 9 months 6 days. 



We see from the above that the longituie of the 

 descending node, or point where the planet crosses the 

 plane of the ecliptic from north to south, is 123" 48 .53 ', 

 which is distant only IF from the perihelion point ; in 

 other words, the planet when nearest to the sun is, at the 

 same time, very near the plane of the earth's orbit, and 

 thus approaches our earth more nearly than it would 

 otherwise do. The following little table gives the least 

 distance of DQ from the earth as compared with those 

 of our other neighbour worlds : — 



„, . . Distance from the Earth 



Ubject. jjj astronomical imits. In miles. 



The Moon 0-0026 238,000 



The Planet DQ ... 0143 13,300,000 



Venus in transit ... 0-264 24,500,000 



Mars in perihelion ... 0372 34,600,000 



The fact that makes the new planet so absolutely unique 



is that its mean distance from the sun is less than that 



of Mars ; there are two or three of the group of asteroids 



whose perihelion points lie just inside the orbit of Mars ; 



but in all other cases their mean distances considerably 



exceed his. 



Dr. Berberich has compared his elements with all the 

 observations of the planet made during August, and finds 

 a very satisfactory agreement. It will, however, be under- 

 stood that the planet has not yet been under observation 

 sufficiently long to determine the elements with perfect 

 accuracy, and those given above must be regarded as only 

 a first approximation. It is desirable to keep the planet 

 under observation as long as possible ; large instruments 

 will probably be able to follow it till the end of November, 

 or even longer. The following table gives its approximate 

 place at llh. p.m. on certain days in November : — 



We may thus hope to obtain, even in the present year, 

 a considerably more accurate determination of the orbit ; 

 but in the meantime we may provisionally treat the above 

 elements as accurate, and deduce from them some in- 

 teresting conclusions. 



First as to the dimensions of the new planet. It was 



