HENRY S()THERAN & CO., 140. STRAND, W.C, and 43, PICCADILLY, W. 779 



15472 WATSON (Sir William, m.d., f.r.s.) Experiments and Observations tending to illustrate 

 t>he Nature and Properties of Electicity, first edition, 8vo. (pp. 67), sewn, Is 6d 1746 



' He notices therein that although ice, as well as Avater, is an 'electric ' or non-conductor, moist air conducts, and he 

 explains thereby the failure of electrical experiments in wet weather.'— D. iV^. B. 



15473 Another Copy; with the Sequel, wherein is presumed, by a Series of Experiments 



expresly [sic] for that Purpose, that the SOURCE of the Electrical Power, and its Manner of 

 acting are demonstrated, toith folding copperplate of the author's electrical machine, consisting of 

 four glass balls (pp. 80)— 2 vols. 8vo. sewn (rare), 17* Qd 1746 



15474 Second Edition, with the Sequel, with folding copperplate, 2 vols. 8vo. sewn, 15s 1746 



'He shows in his Sequel by his own own experiments and those of his Iriend John Bevis that the 'stroke' of the 



recently discovered Leyden jar was, caeteris paribus, proportional not to its size, but to the conducting surfaces of its 

 coatings. He notices that the 'electric force always describes a circuit', and propounds the theory that in an electricai 

 machine the glass globes, etc. have not the electrical power in themselves, but only serve as ' the first movers and 

 determiners of thac power '. He agrees with the Abbe Nollet in regarding electricity as existing normally everywhere 

 in a state of equilibrium, and regards the electrical machine as comparable to a pump which accumulates electricity on 

 t^e bodies we term 'electrified.' Wat.son's theory, though less clearly formulated, is hardly distinguishable from that of 

 Benjamin Franklin.'—/;. N. B. 



15475 Third Edition, Svo. seun, Qs Qd 1746 



' Watson's electrical experiments became famous outside scientific circles. George III. (then Prince of Wales), the 

 Duke of Cumberland (' the Butcher 'j, and other fashionable people went to see them at his house in Aldersgate Street.' 

 —D. N. h. 



15476 WATTS (William Marshall, d.sc . f.i.c.) On the Atomic Weight of Radium, and on 

 Relationships hetween the Atomic Weights of the Elements and their Spectra, 8vo. (pp. 6), sewn, 

 \s Qd 1904 



15477 On the Existence of a Relationship between the Spectra of some Elements and the 



Squares of their Atomic Weights, 8vo. (pp. 5), sewn, \s %d 1903 



15478 Index of Spectra, with Preface by Sir Henry Enfield Roscoe, f.r.s., with 9 plates 



(1 coloured), Svo. cl. {scarce). Is 6rf 1872 



15479 Revised Edition, greatly enlarged, with Introduction on the Methods of Measuring 



and Mapping Spectra, with folding plate, 8vo. cl. (scarce), £1. I* Manchester, 1889 



'The object of this book is to facilitate spectroscopic research by collecting all existing measurements of the spectra of 

 the elements, and presenting them on a uniform scale of wave-lengths.' — Preface. 



The above edition contains the Briti-sh Association Wave-Length Tables of the Spectra of the Elements and their 

 Compounds (1S84-8), with important additions, and incorporates the results of Thalen's researches in ' Sur le Spectre du 

 Fer,' and Fievez's ' Sur le Spectre du Car bone.' 



15480 Introduction to the Study of Spectrum Analysis, with coloured plate and 35 other 



illustrations, Svo. cl., %s Qd (p. 10* Qd nett) 1904 



Including a ' Catalogue of Spectra ' (pp. 185-310), and an Appendix by Sir William and Ladv Huggins. 



15481 On the Spectrum of the Bessemer Flame, with 2 plates, Svo. (pp. 10), sewn, with 



inscr. to Sir Edward Thorpe, F.E.S., 2s 1873 



15482 , and H. M. WILKINSON : On the Swan Spectrum, Svo. (pp. 5), sewn, is 6d 1906 



15483 WEBBER (William Hosgood YouDg, c.E.) Town Gas and its Uses for the Production of 

 Light, Heat, and Motive Power, ivith 71 illustrations, Svo. cl., Ss 6d (p. 6s nett) 1907 



15484 WEBER (Heinrich; Univ. Strasbourg), Josef WELLSTEIN, und Rudolf H. WEBER : 

 Angewandte Elementar-Mathematik ; with 358 illustrations, Svo. cl., with Dr. Emil Reich's 

 bookplate. Is ed (p. M. 14) Leipzig, 1907 



15485 WEBER (Jakob Andreas) Anmerkungen iiber die Sammlungen von der Nachrichten und 

 Beobachtungen iiber die Zeugung des Salpeters, nebst Sendschreiben iiber dessen theoretische 

 und praktische Abhandlung von dem Salpeterzeugen, von Z. Winzler, post Svo. sew7i, ds 



Tubingen, 1780 



15486 Physikalisch-CHEMISCHES Magazin fiir Aeizte, Chemisten und Kiinstler, I. Theil, 



post Svo. sewn, 3s Berlin, 1780 



15487 Vollstandige theoretische und praktische Abhandlung von deni Salpeter, und der 



Zeugung desselben, nebst Abhandlung von der Gahrung, durch physische und chemische 

 Grundsatze und Erfahrungen bestiitiget, post Svo. sewn, 5s Tubingen, 1779 



15488 WEBER (Joseph ; Generalvicar v. Augsburg) Der Galvanismus und Theorie desselben, post 

 Svo. (pp. 64), setvn, 'Is 6d ' Miinchen, 1815 



There is no copy of this work in the Ronalds Library. 



15489 WEBER (Robert, Univ. Neuchdtel) Graduated Collection of Problems in Electricity, 

 comprising all Branches of Electrical Science, translated by Edward A. O'Keeffe, M.I.E.E., with 

 diagrams, cr. Svo. cl., 4s (yd (p. Is %d nett) 1902 



15490 WEBSTER (William, Writing -Master) Arithmetick in Epitome: or a Compendium of all 

 its Rules, both Vulgar and Decimal, with clear and plain Demonstrations deduced from the 

 Principles of Arithmetic itself; without either Reference to Euclid, or Use of Algebra; 6th Edition, 

 carefully corrected, with 7 tables on copper, 12mo. contemporary calf [joints cracked), 6s 1740 



Dedicated to Sir Robert Walpole. 



15491 The Description and Use of a Complete Sett or Case of Pocket-Instruments : 



containing the Construction of the several Lines laid down on the Plain-Scale, and Sector ; with 

 their Application, 2nd Edition, corrected, with \ folding copperplates, Svo. (pp. 61), sewn, 5s 1739 



15492 Third Edition, corrected, with 4 folding plates, Svo. sewn. As n. d. 



15493 Fourth Edition, corrected, with A folding plates, Svo. sewn, uncut, As 1768 



15494 Essay on Book-Keeping, according to the True Italian Method of Debtor and 



Creditor, hy Double Entry, wherein its Theory is clearly laid down in a few plain Rules ; and 

 the Practice made evident and easy, by Variety of intelligible Examples ; 11th Edition, by Ellis 

 Webster, sm. Svo. old calf {binding damaged) Is 6d 1752 



