This is a reproduction of a library book that was digitized by Google as part of an ongoing effort to preserve the information in books and make it universally accessible. https://books.google.com NYPL RESEARCH LIBRARIES | 34.33 ||||| O691091 – ！！ ！！ ！！ ！！ ！ 2 _- - * - _º º 4.WN iſ A. N. U A ſ, _-_ — of -- … – ( Z.Z.º. cºlºſ Cſºlº, Ayſal & AyA.T.ſ. 5 ºf – ~ - an or sº w - -- > __ anº's ( // E *ſ'. E. O.A.: O I, O & Y. - - º Az _º_*zº, _{Z ~4–. _4% • *. %2. zz & C//4///:3' W. W.4/, /ſ/.../º, SºCſ. ET4/ºr 7, 17//, //, //7/2/, //, 5, , , ,77. //, /wo ºrºzzes *A ºl. II. - - - - - - - - - - - - - - - - - - - - - - - - - - - - --- - Tonoon: . * ~ * - - - - - - - - - - - ------ - -> --> * > *.*.*.*, *, * * x - M.A is . .” - P. i. i* - lº Hº -- - - - - - - -- - - - - * ~ * - - - - 2. - THE NEW YORK PUBLIC UIBRARY Astor, ‘f Nox TIL CEN FOUND A TY ONº. *- **º----- ADVERTISEMENT, IN presenting this volume to the public, it is only just to the publishers for me to state, that the long interval which has elapsed between the appearance of the first and the second volumes has arisen from causes over which they had no control. Circum stances having rendered it necessary for them to seek assistance to complete the volume, I was in duced, at their request, to undertake it: and all that Dr. Lardner had contributed was forthwith placed in my hands. It is unnecessary for me to state the difficulties which an author must encounter in attempting to complete a work commenced by another. I must, however, mention that, after a careful examination of the materials placed at my disposal, I have en deavoured to carry out Dr. Lardner's original de sign, as developed in the Introduction to Vol. I.; and shall now point out, as distinctly as I can, the nature and extent of my own contributions to the present volume. In the early pages of the work, (a considerable portion of which was in type when I undertook its completion,) I have placed within brackets my own words, whether they be interpolations or con densed matter. I have also added extra chapters to this portion, – as Chap. XV. of Book I, On the WOL. II. A. vi AD VERTISEMENT. Electricity of Steam; Chap. VIII. and IX. of Book II., On Faraday's Researches, – and Memo randa which had not been included elsewhere; and throughout the volume I have appended many para graphs, to supply deficiencies or to illustrate parti cular points. In order still further to mark the distinction between Dr. Lardner's contributions and my own, in the Table of Contents I have placed a star (*) at the head of every chapter and paragraph which are entirely his; the interpolations being, as before, indicated by brackets. A few pages of Voltaic Electricity, comprising the first two paragraphs of Chap I., and Chap. II. to para graph 310., are from the pen of Dr. Lardner. I used my own judgment in the continuation, adopting the arrangement and selecting the materials which were best suited to my limits; and my reason for quoting so frequently the words of other writers, instead of giving my own descriptions, is because that method allowed of my introducing smaller type, and in cluding much matter for which I could not other wise have found space. I have brought up the description of Voltaic Combinations to the latest improvements, including Grove's Gaseous Battery; and have done my best to collect the clearest illus trations of Electrolytic Action, and its applications. The chapter on Dry Piles is chiefly Dr. Lardner's. Magnetism is mine, and of necessity is only a sketch. I found a few wood-cuts prepared, and also the mag netic charts; and have therefore introduced them, with a view of keeping close to the original design. The commencing portion of Electro-magnetism was written ; but it required so much revision and al teration to adapt it to my own views, and to the ADVERTISEMENT. vii circumstances before me, that it may almost be regarded as re-written. The latter portions of this branch, as also its kindred subjects, Magneto- and Thermo-electricity, are mine. In conclusion, I would beg to remind the reader that this is professedly an Elementary Treatise, the chief design of which is to teach, as it were, the alphabet and the first principles of the science. When the student has made himself master of the contents of these volumes, he will find a rich store of electrical discoveries awaiting him; he will see that the science, which but a few years ago had no proper rank of itself, has now become of paramount interest; that, like the disregarded snow-flakes, it moved at first slowly and in obscurity; but now, like the mighty avalanche, it has advanced with a power and rapidity of which it originally gave no indication. CHARLES W. WALKER. London, Feb. 1st, 1844. *- ANALYTICAL TABLE OF CONTENTS. VOL. II. The chief portion of the Paragraphs or Chapters marked thus * is Dr. Lardner's. BOOK THE FIRST. ELECTRO-STATICs — continued. * CHAPTER x. ConDENSERS. Page (221.) Induction the Origin of Condensers - - - 1 (222.) Illustration of the Condenser - - - - 2 (223.) Theory of the Condenser - - - - 8 (224) Effect of approximating the Discs of the Condenser - 4. (225.) Means of retaining a Charge on the Condenser - 4 (226.) Use of Condensers - - - - - 5 (227.) Comparative Rank of Condensers - - - - 5 (228.) Description of a Condenser - - - - 5 (229.) Mode of manipulating - - - - - 6 (230.) Latent or dissimulated Electricity - - - 6 (231.) Free Electricity - - - - - 7 (232) Formula for the disguised Electricity of the Collecting Plate - 7 (233.) Formula for the whole Charge of the Collecting Plate - 8 (234.) Formula for the Power of a Condenser - - - 8 (235.) Illustration of free and disguised Electricity - - 9 (236.) Reciprocal Variations of these Effects - - 10 (237.) Variation from imperfect to perfect Charge - 10 ANALYTICAL TABLE OF CONTENTS, (238.) Formulae for perfect Charge - 1 (239.) The Power of a Condenser to be determined by Experiment - 12 (240) Advantage of large Condensers - 12 (241.) Glass used in Condensers - 12 (242.) AEPINUs's first Condenser - 13 (243.) CUTHBERTSON's Condenser - 13 (244.) Condensing Plates to be parallel during Separation - - 14. * CHAP. XI. ELECTROSCOPIC INSTRUMENTS. (245.) Electroscopes and Electrometers defined (246.) Coulomb's Electroscope - (247.) GILBERT's Needle Electroscope (248.) Volta's Straw Electroscope (249.) HENLEY's Quadrant Electrometer (250.) BENNETT's Gold Leaf Electroscope (251.) CAVALlo's atmospheric Electroscope (252.) CAvAllo's portable Electroscope (253.) Condensing Electroscopes (254.) BENNETT's condensing Electroscope (255.) Delicate condensing Electroscope (256.) BecqußRel's condensing Electroscope, with large Plates (257.) BohenBERGER's condensing Electroscope (257'.) PECLET’s electrical Condenser i (257''.) GAssiot's double Electroscope * CHAP. XII. THE ELECTROPHORus. (258.) Another Application of Induction (259.) Theory of the Electrophorus (260) Construction of the Electrophorus (261.) Mode of using the Electrophorus (262.) Hygrometric Effects of the Atmosphere (263.) To retain a Charge in the Electrophorus (264.) To charge a second Electrophorus with apposite Electricity (265.) Figures of Lichtenberg Composition for Electrophorus Power of the Electrophorus i (267.) ANAdyTICAL TABLE OF CONTENTS. xi. # CHAP. XIII. The LeYDEN JAR. Page (268.) Theory of, and Formulae for, the Leyden Charge - - 37 Effect of Dis (269.) Influence of the Thickness of the Glass, and - - - 40 charge - - - (270.) Leyden Experiment the same in Principle under Various - - - 41 - - Forms - - 41 (271.) Leyden Jar, or Leyden Phial - - - (272.) Comparison between Leyden Jar and condensing Plates - 42 - 42 (273) Illustration of the Leyden Phenomena - - - 44 (274.) Charge given to the outer Coating - - - 45 (275.) Gradual Discharge by Convection - - (276.) Neutralization of two charged Jars by Connection - - 46 - 47 (277.) Mode of charging Jars - - - - - 48 (278.) RichMANN's charged Plate - - - - 51 (279) Use of the conducting Coatings -. - - (280) Place of the Electricity constituting the Leyden Charge - 51 - - 52 (281.) One Method of determining it - - - 52 (282.) Another Method, by movable Metal Coatings - - 53 (282.) Faraday's dissected Gauze Leyden Jar - - - 54 (283.) Leyden Jar for retaining a Charge - - - - - 55 (284.) Spherical Jar - - - - 55 (285.) Fxtemporaneous Jar of Tin and Wax - - - - - 55 (286.) Consecutive Leyden Charges - - 56 (287.) Formulae for consecutive Charges - - - - - 56 (288.) Electrical Cascade, and Formulae for it - (289.) Consecutive Charge converted into condensed Discharge; and - - - 57 its Formulae - - - - - 58 (290) Leyden Battery- - - - 59 - - - (291.) Battery Discharge - - 60 (292) Mode of indicating the Progress of the Charging - - 61 (293) Spontaneous Discharge - - - - - 62 (294.) Illustrated by charged Jar in Vaccu - - - 62 (295.) Formula for the Leyden Charge - - - 62 (296.) Deflagration of Wire - - - - (297.) Mode of increasing the Capacity of a Jar for Charge - - 63 - 63 (298.) LANE's discharging Electrometer - - - 64 (299.) HENLEY's universal Discharger - - - (300) Cuthbertson's Balance discharging Electrometer - - 65 - 67 - - - (301.) CAvAllo's Multiplier - - 69 (302.) Nicholson's spinning Condenser - - - xii ANALyticAL TABLE OF CONTENTs. * CHAP. XIV. ExPERIMENTS ILLUSTRATING ELECTRICAL ATTRACTION AND Repulsion. Page (303.) Introductory - - - - - - 71 (304.) Exp. I. Application of the Hand near a charged Conductor - 71 (305.) Exp. II. Suspension of a Pith Carrier Ball between a charged and an uncharged Conductor - - - - 71 (306.) Exp. III. Electrical Bells - - - - 72 (307.) Exp. IV. Skein of Silk on the prime Conductor - - 73 (308.) Exp. V. Pith Balls within a charged Tumbler - - 73 (309.) Exp. VI. Dancing Figures between Discs - . 74 (310.) Exp. VII. Eleetrified Water passed through a capillary Tube 74 (311.) Exp. VIII. Electrified wet Sponge - - - 75 (312.) Exp. IX. Electrified Sealing Wax - - - 75 CHAP. xv. on THE ELECTRICITY EVOLVED BY THE FRICTION OF WATER. AND STEAM AGA inst OTHER BODIEs. (313.) Spark first observed (1840) from a Jet of Steam - - 76 (314.) Mr. ARMSTRONG's original Experiments - - - 76 (315.) Experiments to discover the Locality of the Electrization - 77 (316.) PATTINson's Experiments; Insulation of the Boiler, &c.