40 GENERAL INDEX. 



"Pape 



Simple microscope, theory of ..... OPT. INST. . 33, 43 



galvanic circles described .... GALV. . . 2 4 



Sines, the law of, explained ...... NEW. OPT. . . 7 



SINGE K'S electrical column ..... GALV. . . 26 



Singular prismatic phenomenon, account of ... NEW. OPT. . . 38 



Six's register thermometer ..... THERM. . . 35,36 



SMEATON'S micrometer-thermometer described . . THERM. . 18 20 



Smoke and steam, cause of their ascent . . . POP. INT. . . 8 



SNELLTUS'S discovery of the laws of refraction . . NEW. OPT. . . 7 



Snow, hail, and vapour, cause of . POP. INT. . . 61 



Solar microscope, description of . . POP. INT. 99. OPT. INST. . 50,51 



. . rays, their influence on magnetism . . . ELECT. MAGN. . 97 



. . and sidereal time distinguished . . . POP. INT. . 48, 49 



Solenoid, electro-dynamic, description of . . . ELECT. MAGN. . 79 



Solid parts of bodies not touched by the rays of light . NEW. OPT. . 55 



. . bodies less affected by gravity than fluids . . POP. INT. . . 56 



Solids, tables of the comparative expansions of seven, by heat THERM. . . .27 



. . capable of conveying sounds by the vibration of their 



particles ...... POP. INT. . . 71 



Sonorousness of bodies owing to their elasticity . . --- . 71 



. . effects of, illustrated "... -- . . 71, 72 

 Sound which accompanies the transference of the electric fluid, 



variously measured ....... ELECT. ... 25 



. . various remarks on ..... POP. INT. . . 69 73 



.. caused by the tremulous motion of the air . . -- . . 71 



. . conveyed by the undulation of liquids . . --- . . 71 



the vibration of the particles of solid bodies -- . . 71 



.. its velocity about 1142 feet in a second . . -- . . 72 



not materially different, whatever is the 



direction of the wind .... - . . 72 



. . harmony, or concord of, how produced . . -- . 



Spar, Iceland, its double refraction discovered by Bartolinus NEW. OPT. . 9 

 Spark) electric. See Electric spark. 



Speaking trumpet, principle of its construction . . . POP. INT. . 72, 73 



Specific gravities of bodies explained .... -- . 59, 60 



Spectacles, when invented ...... OPT. INST. . 8 



periscopic, described ..... -- . 9 



Spectral colours, when re-united, produce white . . . NEW. OPT, . . 35 



Spectrum, prismatic, described . . . , . -- . 15 



Specula, qualities and proportions of, metals for-*- " . . OPT. INST. . 29 



method of grinding and polishing . . . -- . 30 



Spherical aberration in lenses, cause of NEW. OPT. 7, 8, 27. - - - . s&\ 



, , in mirrors . . . . . - - 



is in the inverse ratio of the magnifying 



power ........ --- 



in lenses, minimum of 





r comparison of, in glass, sapphire, and 



diamond ...... - 



Springs and fountains, their origin, &c. .... POP. 



.. intermitting, accounted for . . . " V ^ 

 Stands, or supports, for telescopes, construction of 

 Stars, fixed, their size and distances unknown 

 Statical thermometer, description of ... 



Steel. See Iron. 



Steel-bar, effects of a transmission of electric fluid throu 

 Steelyard, its principle and application . ^ , 

 Stereo-electric currents, definition of . ^ 



Stone, falling, is met on its way by the earth . 

 Stones, electrical quality of some species described 



Structure and functions of the eye . . POP. I> " 3 



Siibslances, transparent, table of the refractive and dispi; 



powers of ........ ;^ .25 



Sulphttric acid, dilute, its action upon copper and on zimf' . 14 



SUTLER, the first author who noticed any of the effects ^T| 



galvanism ...... . 



Sun, the earth nearer to in winter than in summer . . vfcp. INT. 



.. eclipses of, explained ...... -- . 51,52 



. . why he appears red through a fog . . . . 



Sun's rays, their obliquity the cause of the' diminution of 



their heat ,.,,... -- . 46, 47 



