162 



DISCOVERY 



mainly zinc sulphide. WTien a high-tension discharge 

 was applied to the apparatus the zinc sulphide became 

 luminous, doubtless owing to excitation by ultra- 

 violet rays. This experiment is of historic interest 

 (although Ebert's experiments would appear to have 

 led to no practical development in this form of light- 

 source) in view of the results stated to have been 

 obtained by a French scientist, M. Risler. Of these 

 experiments we must await further technical details. 

 According to accounts published in the daily press 

 Risler utilises a discharge through tubes (about 6 yards 

 long) containing rarefied gases and coated with a 

 fluorescent mixture having zinc sulphide as its main 

 base. The combination is stated to have proved 

 highly efftcient. 



Theoretically the production of a cold light in this 

 way appears promisitig. But although the presumable 

 absence of heat-radiation is a favourable factor, there 

 are other difficulties. We have still to determine 

 what proportion of the electrical energy applied to 

 produce the discharge appears in a form to which the 

 fluorescent material is responsive. Assuming that the 

 efficiency in this respect is high, we have next to ascer- 

 tain what candle-power is attainable from such materials 

 when excited. Experience of ordinary phosphorescent 

 phenomena does not suggest that a very powerful 

 source of light could be obtained by this means. 

 Phosphorescent and fluorescent effects, though striking 

 when observed in a dark room, are usually of verj' 

 feeble intensity in comparison with incandescent 

 sources. The " ageing " and gradual failure of the 

 material to respond to excitation would also need study. 

 In addition phosphorescent materials almost invariably 

 yield light of a peculiar colour — for example, a few vivid 

 blue or green lines in the spectrum, which would not 

 be very satisfactory for ordinary purposes of illumina- 

 tion, though possibly the difficulty might be overcome 

 to some extent by a combination of materials. 



Most experimenters with fluorescent substances 

 would probably agree that there are formidable 

 difficulties to be overcome in producing a commercial 

 light-source based on this method. Nevertheless, this 

 constitutes a fascinating line of investigation, and 

 further details of Risler 's experiments will be awaited 

 with interest. 



The First Book of 

 Patents 



By S. and J. Harrison 



' Thirty-five thousand applications were granted in 

 1922," the blue-coated official who sits by the door of 



the Patent Office library in Chancer}' Lane informs the 

 curious. If one is impelled by the information to 

 discover how long mechanical invention has been a 

 popular pastime, and what its beginnings were, the 

 red file marked "Patents Nos. 1 to 40 — 1617-1627 " 

 provides entertaining reading. 



The first three specifications in the file are not 

 numbered, and the earliest of them was granted in 

 February 1611. It reads as follows : 



Metallica ; or the Treatise of Metallica Breafly 

 comprehending the doctorine of Diuerse New 1 

 Metallical Inuentions. But especially How to ' 

 Neal, Malt, and work all kinde of Mettle, Oares, 

 Irons, Steeles with sea-coale, pit-coale, earth- 

 coale and Brush Fewell. also a Transcript of 

 His Maiesties letters patent of priuledge. Granted 

 imto Simon Sturteuant for the said Metallical 

 business for one & thirty 3'ears. 



This patent, like all the early ones, was, in its way, 

 quite a literary work. It was not written in the 

 terse, technical language which the patent-agent uses 

 in the drawing-up of a modern specification. Classical 

 allusions and Biblical quotations were frequent. There 

 were occasional references to the Saints. Simon 

 Sturtevant, for instance, starts his specification thus: 



Gentle Reader, I am not ignorant how they 

 that are w'illing to apprehend and assist new 

 buisness are desirous to be satisfied on these 

 points. First concerning the perfect and exact 

 knowledge of the inuention wherein they are to 

 deal and negociate, for as the common prouerbe 

 saith : — " Ignoti nulla cupido." . . . 



Mr. Sturtevant, however, must have got into trouble, 

 as the next patent shows. 



But not that which was published by Mr. 

 Simon Sturteuant upon his Patent, which is 

 now, by order, cancelled and made voyd, by 

 reason of his standing out-lawed at the time of 

 the grant, and so still continuing and his neglect 

 and not performance of the workes. Whereupon 

 Priuledge By Patent is granted by the King's 

 most excellent Megesty to John Rovenson Esqr., 

 for the making of iron and other materials with sea- 

 coale, pit-coale &c., for one and thirty years. . . . 



The third volume in the file, and the first to receive 

 a number, was granted in 1617 to Avon Rathbume 

 and Roger Burges "for a terme of twentie and one 

 years " by " James — by the grace of God Kinge of 

 Englande, Scotland, Fraunce and Irelande." Although 

 the words " Englande " and " Irelande " are each here 

 spelt with a terminal " e " they are written modern 

 fashion during the course of the specification itself. 

 The patent was concerned with the printing of maps 

 and plans, and the following quotation shows the 

 patentees to be full of a pride of city. 



