227. Section of Micro-Spectroscope 436 228. Solar Eclipse, 1869 439 229. The Planet Saturn 441 230. Solar Prominences, No. 1 442 231. Ditto, No. 2 443 232. Section of Amateur Star Spectroscope 444 232_a_. X. Ray Photo of Living Hand, Exposure 4 minutes 446 232_b_. Skiagraph of a Hand by Dr. Roentgen 448 232_c_. Metal objects photographed through Calico and sheet 450 of Aluminium 232_d_. Skiagraph of Layers of various substances 451 233. Portrait of Professor Helmholtz 452 234. Vertical Section of the Eye 454 235. Section of Retina 456 236. Diagram 457 237. Muscles of Eyes 459 238. Diagram 461 239. Diagram 464 240. Diagram 465 241. Ruete’s Ophthalmoscope 466 242. Diagram 467 243. Wheatstone’s Reflecting Stereoscope 469 244. Diagram 470 245. Diagram 471 246. The Telestereoscope 473 247. Lines 475 248, 249. Diagrams 476 250, 251. Diagrams 477 251_a_. Edison’s Kinetographic Theatre 479 252. Portrait of Sir W. Thomson 481 253. A simple Electroscope 485 254. The Gold-leaf Electroscope 489 255. The Leyden Jar 490 256. A Voltaic Element 491 257. Ampère’s Rule 492 258. Galvanometer 493 259. Daniell’s Cell and Battery 495 260. Grove’s Cell and Battery 495 261. Wire Ignited by Electricity 496 262. Duboscq’s Electric Lantern and Regulator 497 263. Decomposition of Water 498