Chusing Senators. The Congress shall assemble at least on red, and on the part of their offices, and other numbers in small part of this Constitution, as under the sense of things.' ******************** XI. THE REV. JAMES MARTINEAU AND THE 'SPIRITS.' THEIR refusal to investigate and apply its brakes. Chapter XII. OPTICS. Lenses--The image cast by, _236_. Conjugate foci, 262. Cornet, 308. Corti, rods of, 274. Coxwell, 348. Cream separator, 381, _383_. Current, reversal of electric, _130_, 131; transformation of, 124. Cushioning of steam, 56. Faraday, Michael, 159. Field, magnetic, 159; magnets, 171; ring, 174. Filters, 374; Maignen, _373_; Berkefeld, 374. Filtration beds, 372. Flute, 308. Flying-machines, 348. Fly-wheel, use of, 249. Spectrum, colours.