Literary and Philosophical Inliiligence. 



60 



steara and time ate lost during the 

 change of stroke, he conceives that the 

 most economical and powerful appro- 

 priation of steaui to the working of 

 machinery may, by these improved en- 

 gines, be effected. 

 To David (tordon, Esq. of the City 



of Edinburgh, rtwrf Edward Heard, 



of Brighton, Sussex, for an Invention 



of a Portable Gas Lamp. — August, 



ISli). 



This invention consists in condensing 

 tiie inflammable vapour by foi'cing it 

 into a stnmg vessel by means of a 

 pump, which vessel forms the body or 

 reservoir of tlse lamp ; and when it is 

 desired to light the lamp, the gas must 

 be i)ermi((rd to issue out by a gentle 

 stream, which is elTected by the peculiar 

 construction of the valve. 



The body or reservoir may be made 

 of any SMl)s(ance which is sutliciently 

 strong to bear the pressure of the con- 

 densed gas, and of any form capable of 

 affording tiie desired strengtii ; a sphere 

 is ])referred, or a cylinder with spheri- 

 cal ends, made suffici^nitly strong, which 

 reservoir may be concealed within a 

 figure. 



The valve or stop-cock is perforated 

 in the usual way ; but the key of the 

 cock is contracted on one side by having 

 two pieces soldered into it so as to leave 

 an opening of a wedge form, for the 

 passage of the condensed gas. 'Thekey 



[Feb. 1, 



is turned by means of an endless sci-ew 

 with a fine thread, working into small 

 teeth upon the circumference of a i-at- 

 chet wheel fixed to the axle of the 

 key, by which means the key is made 

 to turn very slowly. At first, when 

 the gas is very considerably condensed, 

 the key is gently turned, so that only 

 the narrow end of the wedge-formed 

 aperture is brought up, admitting a 

 very small current of gas, but as tii(> 

 gas consumes, its force diminishes, and 

 a larger opening is required, which may 

 be increased by turning the endless 

 screw and bringing uptlie wide part of 

 the wedge-formed aperture. 



Another contrivance proposed is a 

 conical leatlier valve (similar to that 

 in the reservoir of an air-gim) which is 

 to be ]>laced in (he opening of the reser- 

 voir of the lamp and pressed down when 

 re^juired by a finger screw. Tliis lamp 

 is proposed as portable and convenient 

 for dwelling-houses, for carriages, for 

 ships, &c. 



Preparing for the Press. 



A pei'spicuous Account of the Law of Pa- 

 tents, as relates to scientific inveutions ; 

 containiug much useful and interesting ia- 

 forraation to persons desirous of securiu;j; 

 tlieir inventions by patent, those who al- 

 ready hold such patents in possession, or 

 who are about to enibarl< property in patent 

 concerns. By Charles Blunt, Draughts- 

 man of Machinery, Philoso|)hical Instru- 

 rnent Maker, <fec. 



VARIETIES, LITERARY AND PHILOSOPHICAL. 



Including Notices of H'orks in Hand, Domcstif and Foreign. 



THE Index to the first fifty volumes 

 of the Monthly Magazine, is pre- 

 paring wiiii all speed, and will be pub- 

 lished in the ensuing Spring. Selec- 

 tions of the curious, vahiable, and 

 original papers, will also a])pear within 

 the year in five volumes; and it is 

 proposed in future to publish a volume 

 of selections on the completion of every 

 ten volumes. The Index to so vast a 

 body of information, will constitute 

 a species of cyclopcedia of reference, 

 and the selections will necessarily con- 

 stitute one of the most interesting col- 

 lections in the English laaguage. " 



Lord Byron is again about toappeiir 

 in a dramatic poem, called Marino Fa- 

 Hero, Doge of Venice. His Lordship's 

 reputation has been some time on the 

 wane, but his friends speak highly of 

 this drama. 



Dr. PRETTYMA1N' ToMLiNE, lately 

 translated to tl)e Bishopric of Win- 

 chester, tutor of Mr. Pitt, and his pri- 

 vate friend during his public career, 



liaving finished his promised memoirs 

 of that active, but unfortunate minis- 

 ter, the work will speedily be pub- 

 lished. It may be expected to exhibit 

 authentic details, the secret history of 

 his tergiversations, and the political 

 intrigues of an eventful period of his- 

 tory. 



Memoirs of the Last Nine Years of 

 the Reign of George II. ; by Horace 

 Walpole, Earl of Orford. From the 

 original MSS. found in the chest left 

 by his Lordship's will, to be opened by 

 the first Earl of Waldegrave who should 

 attahi the age of 21 after the year 1800, 

 will soon ajipear in 2 volumes 4to. 



In Febriiary will be published, Me- 

 trical Legends of Exalted Characters 

 by Joanna Baillie, Author of Plays 

 on the Passions, &c. 



Aiul at the same time will appear 

 a new edition of " Plays on the Pas- 

 sions," in 3 vols, 8vo. by the same 

 ingenious lady. 



The Travels in Syria and Mount 

 Sinai : 



