INDEX. 551 



, . , . , Page. 



JjigMning-rod on tower, electrical display observed at 391 



Lightning-rod point preferably single 33g 



Lightning-rod protection, the lateral range of 337 



Lightning-rods advantageously connected with gas and water pipes 376, 378 



Lightning-rods for ships safer when passing over the side 341 



Lightning-rods, the conducting power of, not affected by paint __. 843 



Lightning-rods, the flattening of, objectionable 398 



Lightning-rods, the proper construction and conditions of 400, 401 



Lightning-rods, tubular, better than solid ones, if equal in metal.. 399 



Lightning-stroke at Key West light-house, effects of 533, 534 



Lightning-strokes, effects of, observed 376 377 531 



Lightning tending mainly to the surface of conductors 342 



Lloyd, observations by, on terrestrial magnetism, referred to 349 



Local scientific societies, plan of organizing 511 



Lockyer, physical observations by 465 



Logic required in scientific investigation 515 



Loomis, Prof. Elias, investigation of tornadoes by 292, 293 



Lovell, Dr., early meteorological observations directed by 448 



Machines capable of expending only the power furnished them 133, 457 



Magnet with "intensity" coil illustrated . 429 



Magnet with " quantity " coils illustrated 430 



Maille, comparison by, of relative size of cloud particles and rain- 

 drops 247 



Marble not sensibly expanded by soaking in water 243 



Mariotte, water barometer devised by 421 



Mason and Green, observations by, on upper winds in balloon 



ascents 281 



Matter from conductor, transfer of, in electric discharge 836 



Matter in a potential state, the energy of 457 



Matter, the constitution of, considered 89 



Matteucci, direction by, of meteorological system of Italy 451, 453 



Maximum daily temperature about 3 o'clock p. M 181 



Meade, Capt., direction by, of meteorological observations along 



the northern lakes 448 



Mechanical lamps employed in light-houses 496 



Meech, L. W., tables of sun's diurnal intensity by 42 



Melloni, experiments by, on differences in absorbing heat 144 



Melloni, experiments by, on the deposition of dew 251 



Mental qualification required for scientific investigation 5! 5 



Meteorological observations, advantages of 455, 456 



Meteorological observations established by Smithsonian Institution 



in 1849 26 



Meteorological observations, international, inaugurated in 1839 — 22 



Meteorological observations undertaken at U. S. Army posts 24 



Meteorological system for the United States, urged upon Congress. 454 



Meteorolo£cical system of the Smithsonian Institution 448 



