88 SCENERY OF THE HEAVENS. 



the appointed weeks of harvest, and affording useful aid in gathering, in the 

 fruits of the earth. The comparative proportion which the light of the moon bears 

 to that of the sun is a problem to the solution of which the attention of several 

 philosophers has been directed. The whole heavens covered with full moons would 

 scarcely make daylight. From various experiments that have been made, it is supposed 

 that the lunar light is only equal to the 300,000th part that of the sun. Its rays, there- 

 fore, when collected by the aid of the most powerful glasses, have not been perceived to 

 produce the slightest effect upon the thermometer. De la Hire and Couplet, two acade- 

 micians of Paris, on a serene evening, at the time when the moon was full and on the 

 meridian, collected the lunar rays by means of the burning mirror at the Observatory, 

 which has a diameter of three feet, and made the focus fall on the bulb of a thermometer, 

 but no motion was produced in the liquor. Thus, there was no sensible increase of heat, 

 though a power equal to that of three hundred full moons was brought to bear upon the 

 instrument. But, vastly inferior as is the lunar to the solar light, its utility has been 

 appreciated in all ages and countries by both rude and cultivated nations. To those, 

 indeed, who are the least advanced in civilisation, or who are locally situated apart from 

 its aids, its value is the greatest. Owing to the rapid progress of the useful arts among 

 the cultivated races, they have been abundantly supplied with the means of artificial 

 light ; superseding to some extent their dependence upon the arrangements of Nature, and 

 lowering their estimate of the advantage of her provisions. To the inhabitants of London 

 or Paris, whose streets are splendidly illuminated at night, the presence ef the moon is 

 more a matter of ornament than of use. But it is otherwise when the day has closed 

 with the mariner at sea ; the peasant homeward tracking his way through the drifted 

 snow ; the traveller in a strange country ; and the barbarous migratory hordes of men. 

 To such, when the day has departed, the moon pursues her nightly circuit through the 

 heavens in beauty and brightness, as a friend in need, chasing away the gloom, revealing 

 the features of the scenery, and disclosing the right path. To the Lunarians, if such 

 there be, a similar service will be rendered by the earth, which, to those who occupy the 

 presented hemisphere of the moon, will relieve* with reflected light their fifteen days of 

 darkness. The terrestrial world will exhibit to the lunar inhabitants all the phases which 

 their dwelling presents to us, but upon a far grander scale, the earth appearing upwards of 

 three times the size of the sun, and thirteen times greater than does the satellite, to our- 

 selves. Its aspect will be perpetually changing by the rapid rotation upon its axis its 

 tracts of sea and continent being alternately presented ; and provided with instrumental 

 aid as powerful as that which we possess, a lunar dweller may discern various terrestrial 

 phenomena the mighty masses of cloud that are pendent in our atmosphere, the flashing 

 lightning, the fields of ice at the poles, and the occasional outburst of volcanic fires. 



