讀者評論 - 撰寫評論
angle appear attract ball battery body brass bring brought called candle cause charge Charles colours common concave conducting conductor connected CONVERSATION convex course described direction discharge distance double earth effect electric fluid electrified equal excited experiment explained fall figure fixed flow focus formed give glass half hand hold inches inverted iron James kind lens less light look machine magnet magnified manner means meant metals mirror motion move natural needle object parallel pass person piece Plate poles position present principle produced quantity rays rays of light reason reflected refraction represent retina round seen shock side silver spark stand substances suppose surface taken thing thrown tion touch tube turn Tutor wire zinc
第 56 頁 - Thus with the year Seasons return ; but not to me returns Day, or the sweet approach of even or morn, Or sight of vernal bloom, or summer's rose, Or flocks, or herds, or human face divine ; But cloud instead, and everduring dark Surrounds me, from the cheerful ways of men Cut off, and for the book of knowledge fair Presented with a universal blank Of nature's works, to me expunged and rased, And wisdom at one entrance quite shut out.
第 79 頁 - Since c 6 is perpendicular to the glass at *), the angle of incidence is abc ; and as the angle of reflection is always equal to the angle of incidence...
第 4 頁 - How distant some of these nocturnal suns ! So distant (says the sage) 'twere not absurd To doubt if beams, set out at Nature's birth, Are yet arrived at this so foreign world, Though nothing half so rapid as their flight.
第 35 頁 - A lens is glass ground into such a form, as to collect or disperse the rays of light which pass through it. These are of different shapes, and from thence receive different names.
第 291 頁 - As he was sitting with a friend in the open air, an hour after sun-set, they saw a falling, or as it is sometimes called, a shooting star, directing its course towards them, growing apparently larger and larger, till it disappeared not far from them, and, disappearing, it left their faces, hands, and clothes, with the earth, and neighbouring objects, suddenly illuminated with a diffused and lambent light, attended with no noise at all.
第 131 頁 - Yes ; the three glasses next the eye having their focal distances equal, the magnifying power is found by dividing the focal distance of the object-glass by the focal distance of one of the eye-glasses.
第 60 頁 - First the flaming red Sprung vivid forth; the tawny orange next; And next delicious yellow; by whose side Fell the kind beams of all-refreshing green. Then the pure blue, that swells autumnal skies, Ethereal...
第 295 頁 - Even in the depth of polar night, they find A wondrous day; enough to light the chase, Or guide their daring steps to Finland fairs.