■No\'EMBEK 1, 1895.] 



KNOWLEDGE. 



263 



;Q «a (0 30 ZOO 



Burstall's GJalvanometer Scale and Lamp (Hicks's Patent). The 

 scale and lamp has been designed so as to be portable, rapidly 

 adjusted, and to work in the open daylight. The focussing tube is 



carried on a 

 ball joint, and 

 bv means of 

 a sliding tube 

 can be set at 

 any required 

 height ; when 

 the spot of 

 light has been 

 thrown on to 

 the mirror, 

 both these 

 joints ( an be 

 locked, so that 

 focussing can 

 be done witli- 

 out fear of the 

 spot being 

 shifted off the 

 mirror. 



The scale is 

 divided in 



millimetres on ground gla^s, and is capable of adjustment both hori- 

 zontally and vertically, the latter adjustment being by ii cans of a rack 

 and pinion. The source of light is a small glow lamp, worked by two 

 storage batteries. A fine line is etched on the object glass, and this 

 line is focussed on the scale. By means of hinged joints the lamji 

 an^ locale can be folded into a very small compass. I his form of 

 scale and lamp will be very convenient in the labo atory and testing 

 room, and for U'ing with the potentiometer and other portable 

 test ng apparatus. 



1 • ■ 



Alfred C. Kemper, 36, Oxford Street, London. The Kombi 

 Camera and Graphoscope combined. 

 This invention consists of an outer 

 me'al ea«e, 2 inches by 1^ inelies, 

 fitted with a lens having two stops. 

 The inferior contains two film liolders 

 fitted vith a platen for the pnrp.ise of 

 stretching that portion of the surface 

 of the film upon whic'' the exposure is 

 to l)c made and a mat for determining 

 the size and shape of the picture. The 

 camera holds a roll of twenty-five films. 

 Time or instantaneous expos\ires may 

 be made with an ingenious shutter 

 attaclied to the fore part of the 



machine. Bv removing a cap-plate at tlie back tlie machine can 

 be used as a graphoscope. 



Walter George Eent, High Holborn, London. Imjtrovenients in 

 disc engines, particularly suitable as water meters. The working 

 chamber or so-called cylinder is formed in two parts, a and ft, the 



t ottom a being a 

 =i? flat dish with a 



cylindrical boss o^ 

 on its imderside, 

 to provide fo.- the 

 reception of tlie 

 ball e at the centre 

 of the disc or 

 piston d. The 

 sides of the upper 

 part h of the cy- 

 linder are formed 

 of a portion of a 

 sphere, and the 

 top consists of an 

 inverted conical 

 frustum. The 

 inlet and outlet 

 pipes g and h are 

 diametrically 

 opposite to each 

 other, and the inlet 

 and outlet ports _/ and Ic to the cylinder are formed as usual on each 

 side of the partition e. The gearing working the counting and 

 recording apparatus is contained in an oil-filled box m carried by the 

 cover of the outer casing. 



So. 18,2h6. Dated 26<A September, 1894. Accepted \~th August, 

 1895. Sevenjiguret. 



Ci^ess €oIttmn. 



By C. D. LococK, B.A.Oxon. 



Communications for this column should be addressed to 

 C. D. LococK, Burwash, Sussex, and posted on or before 

 the 12th of each month. 



Solutions of October Problem. 



(J. T. Blakemore.) 



Key-move. — 1. Kt to Kt3. 



If 1. ... K to Q5, 2. E to KRl, etc. 



1. ... K to B3, 2. E to KR4, or 2. B x Pch, etc. 



It is most unfortunate that the removal of a White 

 Pawn at QRl, just before publication, has given rise to the 

 above dual, which, by the way, has not been detected by 

 any solver. The alteration was suggested by the Cbess 

 Editor, and approved by the Composer, whose subtle 

 continuation, 2. K to KE4 in reply to 1. ... K to B3, 

 has thus escaped notice and appreciation. 



Correct Solutions have been received from Alpba, 

 H. S. Brandreth, G. A. F., A. C. Challenger, A. H. 

 Walker, W. Willby, E. W. Brook. 



M. Wiedhoft't. — In reply to 1. Kt to KC-lch Black would 

 play 1. ... K to Q5. There is tbtn no mate in two 

 more move^. 



,7. T. Blakemore. — We much regret that though we 

 pointed out one dual we were chiefly responsible for 

 another. 



A. C. Challemjer. — Many thanks. Tlie 3-mover appears 

 below. The sui-mate is reserved for next month. 



G. A. V. — A capture on the opening move is considered 

 a ralher serious blemish, especially if the captured piece 

 was iree to move, tbe diminution of tbe opposmg force 

 being inartistic. A problem of this class is liable to baffle 

 the experienced solver, who naturally tries the checks and 

 captures only when everytliing else has failed. The pro- 

 motion of a Pawn increases the value of the White force, 

 but docs not increase it niiuifiiciilh/. Hence the queening 

 of a Pawn is not usually objected to, unless it occurs as 

 the key-move ; still it is best to avoid it when possible. 



T. A. Brock. — Thanks for tbe problem, which has a 

 distinct and refreshing savour of originality. 



PROBLEMS. 



No. 1. 

 By T. A. Brock. 



Black (12). 



mm ^m m»'- *^ 



■m,. ....... i 





, ■wM IWi 



i"^". 





iil ■ HiH 



^ ^H S ^P .^ ■ >' ■ 



1 m 





White (ftj. 



White mates in two moves. 



