POPULAR MISCELLANY. 



141 



and you have for result a distance relatively 

 very small ; but divide by 8,000 the enor- 

 mous number of leagues which represents 

 the distance of a star, and there still remain 

 a number of leagues too great to permit of 

 the stars being seen by us in a perceptible 

 form. In considering Jupiter, or any of the 

 planets, we are filled with wonder at the 

 thought that this little luminous point might 

 hide not only all the visible stars, but a 

 number 5,000 fold greater — for of stars 

 visible to our eyes there are only about 

 5,000. All the stars of these many constel- 

 lations, as the Great Bear, Cassiopeia, Orion, 

 Andromeda, all the stars of the zodiac, even 

 all the stars which are visible only from the 

 earth's southern hemisphere, might be set 

 in one plane, side by side, with no one 

 overlapping another, even without the 

 slightest contact between star and star, and 

 yet they would occupy so small a space that, 

 were it to be multiplied 5,000 fold, that 

 space would be entirely covered by the disk 

 of Jupiter, albeit that disk to us seems to 

 be an inappreciable point." 



A Scientifie Detective. — One of the most 

 remarkable among recent inventions is the 

 induction - currents balance, briefly de- 

 scribed as follows in the " Athenaeum " : " It 

 consists of two induced currents from sepa- 

 rate induction coils, which are so equal that 

 they neutralize each other. They are con- 

 nected with three elements of a Daniell's 

 battery, with a small clock and microphone, 

 and a receiving telephone. If a piece of 

 metal is placed in one of the coils, the bal- 

 ance of the currents is disturbed, and the 

 clock is heard to tick ; but if another piece 

 of metal, exactly similar, is placed in the 

 opposite coil, the balance is restored, and 

 silence again prevails." From this brief de- 

 scription it will be understood that in this 

 new instrument the phy.sicist has an exqui- 

 sitely sensitive test of the molecular con- 

 stitution of many substances, for it detects 

 the presence of mixtures and alloys, how- 

 ever small the quantity. Hence a scale of 

 qualities may be formed ; and if the value 

 of silver be placed at 115° there can be no 

 question that everything that marks 115° 

 must be silver, 52° will be iron, 40^ lead, 

 and 10° bismuth ; and, further, the instru- 

 ment is at once affected bv magnetism, heat, 



or strain in the substance under examina- 

 tion, and will indicate even the effect of 

 half a minute's rubbing of a piece of metal 

 between the thumb and finger. The induc- 

 tion-currents balance 'u a contrivance of 

 Professor Hughes's. 



Stained Windows. — The method of con- 

 structing stained-glass windows is described 

 as follows in " Chambers's Journal " : " The 

 design of the window being determined 

 upon, and the cartoon or full-sized drawing 

 being prepared, a kind of skeleton drawing 

 is made showing only the lines which indi- 

 cate the shape of each separate piece of 

 glass. It is apparently not generally un- 

 derstood that a window is not one piece 

 of glass, to which are applied the various 

 colors displayed, but a number of small 

 pieces, which are united by grooved lead, 

 which incloses each individual fragment, 

 and that each different color we see is the 

 color of that particular piece of glass, the 

 only painting material employed being the 

 dark-brown pigment used to define the 

 more delicate and minute details. This 

 skeleton or working drawing then passes 

 to the cutting-room, where sheets of glass 

 of every imaginable shade are arranged in 

 racks, each bearing a number, by which a 

 particular tint is known. The drawing 

 being numbered on each separate piece of 

 glass by means of a frame containing small 

 pieces of every shade, and each numbered 

 according to the rack containing the glass 

 of that color, the use of this frame renders 

 unnecessary the tedious process of visiting 

 each rack in search of the particular shade 

 required ; the glass is laid bit by bit on the 

 drawing, and each piece is then cut to the 

 required shape by means of a diamond. 

 After the glass is cut, it passes to the paint- 

 er, who, laying it over the drawing, traces 

 upon it with his brush all the details of 

 features, folds of drapery, foliage, etc., as 

 designed by the artist. But as the action 

 of the weather and the continually varying 

 conditions of the atmosphere would speed- 

 ily remove every vestige of paint if left in 

 this state, it is necessary to sutyect the 

 painted glass to the action of heat by plac- 

 ing it for several hours in a kiln, under 

 the influence of which the paint is fused 

 into absolute afiinity with the glass, and 



