July 6, 1888.] 



SCIENTIFIC NEWS. 



23 



bearing segment in a segmental slot of a plate fixed 

 above the said pivotted segment. 



Lamp.— A velocipede lamp has been patented by 

 Messrs. W. P. Burt and S. B. Edmonds. The object is 

 to prevent the lamp from being affected by the jolting and 

 oscillation of the vehicle to which it is attached. Two 

 metal tubes are fixed to the lamp, in each of which works 

 a metal rod attached to the socket-piece, by which the 

 lamp is held to the vehicle ; at the upper portion of each 

 is fixed a washer of leather, through which the rod 

 passes, and at the lower end of each rod is a leathern 

 plunger ; at the bottom of each tube is an indiarubber 

 buffer. Between the fixed upper plugs of leather in the 

 tubes and the plungers — upon the rods — are fixed spiral 

 springs, so that, when the oscillation takes place, any 

 movement to the lamp is at once counteracted by the 

 springs. In order to secure a perfectly steady and noise- 

 less action, two wing-pieces lined with leather are 

 attached to the socket, these wing-pieces clipping the 

 outside of the metal tubes which act as a guide. 



Electric Measuring. — Messrs. W. T. Goolden and 

 G. Evershed have patented a compensating electric 

 measuring instrument. The object is to make the read- 

 ing of voltmeters independent of temperature, and is 

 attained by winding the coils of such instruments with 

 wires, having different resistance temperature co-effi- 

 cients. For example, the coil of a voltmeter is wound 

 partly with a wire having a small co-efficient, and partly 

 with a compensating wire having a large co-efficient, 

 the latter wire being coupled in shunt to a portion of the 

 former wire in such a way as to cause the current to 

 flow in opposite directions in the two wires. The 

 resultant magnetic field of the combination coil will then 

 be equal to the difference of the fields due to the two 

 wires, and, by observing certain proportions between the 

 resistances and number of turns of the two wires and 

 the resistance of the shunted portion of the wire having 

 the small co-efficient, this difference may be made con- 

 stant for constant pressure on the terminals of the coil, 

 throughout a large range of temperature. 



TECHNICAL EDUCATION NOTES. 



Releasing Horses. — Mrs. A. D. Durell, London, has 

 patented means for releasing runaway horses from 

 vehicles. To apply the invention to a pair-horse carriage, 

 a rock-shaft is mounted in bearing secured to the 

 splinter-bar of the vehicle. This rock-shaft is provided 

 with short arms projecting horizontally, and to these 

 arms are pivotted bolts, which slide vertically through 

 sockets on the front of the splinter bar. The shaft 

 is actuated by a hand-lever placed near the driver's 

 seat. Plates with holes through them corresponding 

 with the holes in the sockets, and provided with a 

 trace-block, fit into the sockets, and are held in place 

 by the vertical bolts. The pole fits into the chop 

 block in the usual manner, and is kept in place 

 by a metal plate secured to the pole. This plate fits 

 over the sockets on the splinter-bar, in which position it 

 is held by two of the vertical bolts. Should the horses 

 become unmanageable, the driver pulls over the hand- 

 lever, and thereby draws up all the vertical bolts, when 

 the pole and trace-blocks become detached, and the 

 horses are freed from the carriage. 



Central Institution of the City and Guilds of London 

 Institute.— During the month of July, 1888, the following 

 summer courses of lectures and laboratory instruction for 

 technical teachers and others will be held in the Institute's 

 New buildings in Exhibition Road : 1. Elementary principles 

 of machine-designing — By Professor W. C. Unwin, M.I.C.E., 

 F.R.S. A course of lectures and drawing exercises to be 

 given daily, Saturdays excepted, from 6.30 to S p.m., and ex- 

 tending over a fortnight, commencing on Monday, July 2nd. 

 2. Practical lessons in organic chemistry, intended mainly 

 for teachers of technological subjects — By Professor Arm- 

 strong, F.R.S., Ph.D. This course will extend over two weeks, 

 from 10 till 4 daily, commencing on July 2nd. 3. The con- 

 struction and use of electrical measuring instruments. — By 

 Professor Ayrton, F.R.S. This course will include experi- 

 mental lectures and special laboratory work. The lectures 

 will comprise the principles and practice of the construction, 

 calibration, and testing for faults of ammeters, voltmeters, 

 ohmmeters, wattmeters, coulombmeters, and ergmeters as 

 used for direct and alternating current systems. The students' 

 practical work will be conducted in a laboratory specially 

 fitted with accumulators, standard instruments, etc., for elec- 

 trical instrument testing, and they will have the opportunity 

 of examining and practically trying all the more important 

 electrical meters at present in ordinary use. It will extend 

 over two weeks, and will consist of six lectures, from 8 to 9 

 p.m., on Mondays, Wednesdays, and Fridays in the fortnight 

 commencing on Monday, July 16th; and also of practical 

 work in the physical laboratories, daily from 2 to 5 p.m., 

 Saturdays excepted. 4. Experimental mechanics — By Pro- 

 fessor Henrici, Ph.D., LL.D., F.R.S. This course will con- 

 sist of lectures and practical work in the mechanical labora- 

 tory, and will extend over two weeks, from 10 to 4, commenc- 

 ing on Monday, July 16th. 5. The principles of bread making 

 — By William J ago, F.C.S., F.I.C., Examiner to the Institute. 

 This course will consist of lectures and practical demonstra- 

 tions, and will extend over two weeks, from 10 till 4 daily, 

 Saturdays excepted, commencing on Monday, July 16th 

 6. Photography — By Captain Abney, R.E., F.R.S., Examiner 

 to the Institute. A course of six lectures, at 8 p.m., on Mon- 

 day, Wednesday, and Friday in the fortnight, commencing on 

 Monday, July 2nd. 7. Mathematical and surveying instru- 

 ments — By Arthur Thomas Walmsley, M.I.C.E. A course 

 of six lectures, illustrated by large scale diagrams and instru- 

 ments lent by various makers, at 8 p.m., on Monday, Wednes- 

 day, and Friday in the fortnight commencing on Monday, 

 July 2nd. 8. Gas manufacture — By Lewis T. Wright, engi- 

 neer to the Nottingham Gas Works. A course of four lec- 

 tures, at 8 p.m., on Tuesday, July 17th; Thursday, July 19th ; 

 Monday, July 23rd ; and Tuesday, July 24th. 9. The Appli- 

 cation of modern geometry to the cutting of solids for 

 masonry and other technical arts — By Lawrence Harvey, 

 Medallist of the Ecole des Beaux Arts, Paris. A course of 

 six lectures, practically illustrated, at 8 p.m. on Monday, 

 Wednesday and Friday, in the fortnight commencing 

 on Monday July 16th. 10. The craft of the carpenter 

 — By John Slater, B.A., Examiner to the Institute in 

 Brickwork and Masonry — A course of four lectures, 

 at 8 p.m., on Tuesday, July 3rd ; Friday, July 6th ; 

 Tuesday, July 10th; and Friday, July 13th. Further par- 

 ticulars and a syllabus of each course may be obtained at the 

 Central Institution, Exhibition Road, S.W., or at Gresham 

 College, London, E.C. 



- — ->-^>!^»^5<f-» ■ 



ANNOUNCEMENTS. 



Ironmongers, Iron and Metal Trades' Exhibition.— 

 An exhibition in connection with these trades is to be held in 

 the Agricultural Hall, Islington, in November next. Tha 

 exhibits are to include household ironmongery of all kinds, 

 lighting, heating, and sanitary appliances, machinery, imple 

 ments, and tools. 





