L 



for the contemplation of Nature, 11, 

 12; powerful impressions, from their 

 organic richness and fertility, 13; 

 facilities they present for a know- 

 ledge ot tlie laws of nature, 14; 

 brilliant displav of shooting stars, 

 100. 



Laugier, his calculations to prove Hal- 

 ley's comet identical with the comet 

 of 1378, described in Chinese tables, 

 95. 



Lava, its mineral composition, 232. 



Lavoisier, 44. 



Lawrence (St.), fiery tears, 111; me 

 tooric stream, 112. 



Leibnitz, his conjecture that the planets 

 increase in volume in proportion to 

 their increase of distance from the 

 Sun, 78. 



Lenz, observations on the mean level 

 of the Caspian Sea, 301 ; maxima of 

 density of the oceanic temperature, 

 309; temperature and density of the 

 ocean under different zones of lati- 

 tude and longitude, 311 



Leonhard, Karl von, assumption on 

 formations of granular limestone, 

 264, 265. 



Leveirier, planet Neptune. See 

 Translator's note, 74 76. 



kewy, observations on the varying 

 quantity of oxygen in the atmosphere, 

 according to local conditions, or the 

 seasons, 317. 



Liehtenberg, on meteoric stones, 105. 



Liebig, on traces of ammoniacal va- 

 pours in the atmosphere, 317. 



Light, chromatic polarization of, 33 ; 

 transmission, 72 ; of comets, 89 91 ; 

 of fixed stars, 90, 9 1 ; extraordinary 

 lightness, instances of, 131 133; 

 propagation of, 143; speed of transit, 

 144. See Aurora, Zodiacal light, 



too. 



Lignites, or beds of brown coal, 286, 

 287. 



Lines, isogonic (magnetic equal devia- 

 tion), 170, 174178; isoclinal 

 (magnetic equal inclination), 171. 

 172, 174 178; isodynamic (or mag- 

 netic equal force), '174, 178 188; 

 isogeothermal (chthonisothermal), 

 216; isobarometric, 321 ; isothermal, 

 isotheral, and isochimenal, 323 

 835, 867. 



Line of no vaiiation of horary declin 

 tion, 176; lower limit of perpetual 

 snow, 336 340; phosphorescent, 

 99. 



Lisbon, earthquake of, 206, 207, 209, 

 210. 



Lord, on the limits of the snow line on 

 the Himalayas, 11. 



Lottin, his observations of the Au- 

 rora, with Bravais and Siljerstrom, 

 on the coast of Lapland, 190, 194, 

 196. 



Lowenorn, recognised the coruscation 

 of the polar light in bright sunshine, 

 190. 



Lyell, Charles, investigations on the 

 numerical relations of extinct and 

 organic life, 279; nether- formed or 

 hypogene rocks, 249 ; uniformity of 

 the production of erupted rocks, 2o7. 

 See notes by Translator, 198, 243, 

 257. 



Mackenzie, description of a remark- 

 able eruption in Iceland, 234. 



Maclear, on a Centauri, 71 ; par- 

 allaxes and distances of fixed stars. 

 143; increase in brightness of 17 

 Argo, 144. 



Madler, planetary compression of 

 Uranus, 80; distance of the inner- 

 most satellite of Saturn from the 

 centre of that planet, 82; material 

 contents of the Moon, 80 ; its libra - 

 tion,83; mean depression of tempera- 

 ture on the three cold days ot May 

 (llth 13th), 121; conjecture that 

 the average mass of the larger num- 

 ber of binary stars exceeds the mass 

 of the Sun, 139. 



Magellanic clouds, 69. 



Magnetic attraction, 182; declination, 

 174176; horary motion, 170 

 172; horary variations. 176, 184; 

 magnetic storms, 170, 172, 189, 194; 

 their intimate connection with the 

 Aurora, 187 196, represented by 

 three systems of lines, see Lines ; 

 movement ot oval systems, 175, 176 

 magnetic equator, 176 178; mag 

 netit: poles, 176, 177; observatories 

 1841 86; magnetic stations, 184, 

 185, 323. 



Magnetism, terrestrial, 169187, 18* 

 electro, 169184. 



