LIST OF ILLUSTRATIONS. 



xvii 



Fig. Page 



ating Cord 535 



.. Vibrating String showing Nodal 



Points 536 



252. Ditto 536 



253 256. Lines of Sand on Plates 538 



257. The Siren 539 



258. Professor Helmholtz 543 



259. Reiss's Telephone 545 



260. Graham's Speaking Telephone 546 



261. Volta 548 



262. Galvani's Experiment 550 



263. Ditto 552 



264. Voltaic Pile 553 



265. The " Crown of Cups " 554 



266. Davy's Experiment 556 



267. A Voltaic Element 556 



268. Volta's Experiment 558 



269. Daniell's Voltaic Cell 559 



270. Bunsen's Battery 559 



271. Ditto showing mode of connection... 560 



272, 273. (Ersted's Experiment 561 



274. Ampere's Rule 562 



275. Andre Marie Ampere 563 



276,277. Electro-dynamics 564 



278. Currents in a Magnet 565 



279, 280. Solenoids 565 



281, 282. Coils 566 



283. Electro- Magnet 567 



284. Sommering's Electric Telegraph 568 



285. Galvanometer 570 



286. Needle Telegraph 571 



287. A Galvanometer 572 



288. Transmitting a Message 573 



289. Receiving a Message 574 



290. The Galvanometer 575 



291, 292. Faraday's Experiment 579 



293. Magnet producing a Current 580 



294. Magneto-electric Machine 581 



Fig. . Page 



295. Gramme Machine 582 



296. Induced Currents 584 



297. Ruhnikorff's Coil 585 



298. The Stratified Discharge 587 



299, 300. Thermo-Electric Currents 590 



301. Mirror Galvanometer 591 



302. Armstrong's Hydro-electric Machine 591 



303 Hpltz Machine 592 



304. Ditto 593 



305. Liebig 595 



306. John Dalton 603 



307. Symbols for Gases 604 



308. Davy 605 



309.-j>Decomposition of Water by Elec- 



^s tricity 608 



"310. Davy's Safety Lamp ,. 612 



311. Jacob Berzelius 614 



312. Dumas' Synthesis of Water 619 



313. Faraday's Gas-condensing Apparatus 623 



314. Hofmann 624 



315. Eudiometer 627 



316. Apparatus for decomposing Steam... 628 



Tail-piece Bust of Dalton 628 



317. Charles Robert Darwin 635 



318. Scolopendra angulata; Scolopendra 



variegata 637 



3i9^*-Leaf Insect (female) 641 



4^^ Walking-stick Insect 642 



-321. Pasteur 647 



322. Bone Cavern 649 



323. Fortin's Barometer 651 



324, 325. Preparation of Thermometers... 654 



326, 327. Hygrometers 655 



328. Psychrometer 656 



329X-Rain-gauge at the Observatory at 



yf Paris 657 



330. James P. Joule 659 



331. Sir William Thomson 665 



