June 5, 1j>65.1 



• KNO^A^LEDGE ♦ 



491 



ii^nv lubnitoie' Column. 



We give here, ireet by \ceel; a terse defcriptioyi of such of tlie many 

 inventions as we think may he of use to our readers, ^yhero it is 

 possible, the number of the patent is quoted, to fiia!i!o those who 

 desire fuller in/ormafioii to procure the specification from the 

 Patent Ofice in Cursitor-street, Chancery-lane. H'e shall, gene- 

 rally speaking, confine ourselves to the more recent inventions; but 

 it often happens that an article coiiii-s «iu!cr our notice which, 

 although not quite novel, is worthii of mention for its utility and 

 ingenuity. In such a case we should 7iot hesitate to refer our 

 readers to it. And while we thus increase the interest of our pages, 

 tee at the same time assist the inventors by giving greater publicity 

 to their inveni 'ns (Knowledge being a popular magazine) than 

 is accorded by the most excellent trade journals. 



MICKOSCOPES. 



Messrs. M. Theiler & Sons, of SO, Canonbury-road, London, N., 

 are just now introducing two microscopes new to the English 

 market. One of them is called the ''Demonstration" microscope, 

 and is expressly designed for use in schools and in the drawiug- 

 i-oom. It has three powers, magnifying 30, 100, and 150 diameters 

 respectively. The construction is very simple, and the workman- 



In tho case aio also a good botanical lens (magnifying six diamo- 

 tors), three specimen slides, two empty slides (for sceuring prepa- 

 rations to bo examined), and a third slide provided with a cavity 

 (tor holding a drop of water or any olher liquid). This instrument 

 is a virtual microscope, giving beautifully-dcliued images, and, like 

 tho Demonstration Microscope, may bo used either by the aid of 

 day or lamplight. No one having any interest in microscopy should 

 leave home unaccompanied by such a small and so efficient an in- 

 strument. Us cost may bo measured in tho inverse ratio to its 

 utility and value. 



PARALLEL GKIl' VICE. 

 This tool, introduced by tho Coventry Machinists' Company, is a 

 simple form of the latest innovation in tho way of vices. A series 

 of transverse notches or screw threads is cut on the under side of 

 the slide (which is of square or rectangular section). Correspond- 

 in"- threads are cut in a piece of steel or iron at the bottom ^f tlu' 

 slot in tho back jaw. The front jaw can, and is only required to 

 lie, moved a very short distance along the slide, this movement 

 being effected by turning tho lover handle one way or tho other. 

 To fasten an article in the vice, all that is necessary is to hold it 

 between the jaws with on'o hand, and raising tho loose or front 

 jaw (and tho slide with it) with the other hand, push it into 

 contact with tho article. The threads on tho slide dropping into 

 the threads in the slot of the back jaw, all that is necessary is to 



The " Demonstration " Microscope. 



ship of the best. The ocular tube or eye-piece slides into another 

 tube, a, which carries the object-glasses, and which in its turn 

 slides into the split tube, b, being held in position by the clamping- 

 ring, «, which screws on to a slightly-tapered thread on h. It will 

 be observed that the instrument is used by holding it against the 

 light, which passes through a small hole in the lid or diaphragm, </. 

 A highly-poUshed concave mirror (with a central hole for the 

 passage of light and of the object-glass) is fitted in c, being pressed 

 forivard by means of a spring. Two segmental strips of metal are 

 fastened to the rim of c, and the slides are held between these 

 strips and the mirror by the aid of the spring already mentioned. 



The instrument being duly focussed, it may be handed round to 

 any number of persons, each spectator adjusting for his own eye- 

 sight, if necessary, by the ocular tube, no other alteration being 

 necessary. It must be seen that the convenience of manipulation 

 is all that could be desired, while no praise we could bestow upon 

 the instrument, either as a piece of mechanism or as a microscope, 

 would be too great — that is to say, within its own sphere. It is 

 cheap, and certainly superior to many other instruments of a 

 considerably higher price. 



The other instrument of Messrs. Theiler is called the Universal 

 ''Pocket" microscope, which magnifies fifty diameters. It is en- 

 closed in a case measnring about 2^ in. square and about J in. deep. 



Carriage Readiug-Lamp. 



secure the article rigidly. This is done by giving a half-turn to 

 the handle in front, when the hole will be screwed together tightly, 

 the jaws being at all distances parallel. To release the .article tho 

 handle is unscrewed half a turu, tho front jaw slightly raised, and 

 the slide withdrawn to any desired distance. Tho vices are well 

 made and simple in construction, while there is little or nothing to 

 get out of order. 



CARRIAGE EEADIXG-LAMP. 



[Patent 0,92.5. 1881.] — This lamp has been patented by Mr. 

 Hartshorne, of 39, Newhall-street, Birmingham. It is hold in 

 position by means of a vice, which is made to grip the front of a 

 railway-carriage cushion, easy-chair, sofa, sliip's cabin, seat, or any 

 other suitable support. An arrangement of telescopic tubes carries 

 the tube which contains tho candle. The candle is raised during 

 combustion by a spiral spring. When in use, tho height of tho 

 light can be adjusted by the telescopic tubes, and, for convenience 

 of packing, the whole apparatus can be closed into a small box 

 three inches wide, one and a-h,alf deep. A semi-circular reilector, 

 which easily turns with the candle-tube, enables tho reader to con- 

 centrate tlie light on any desired part. The lamp is well and 

 strongly made, is very durable, and should commend itself to 

 travellers. 



