A tumbler filled with water, may be whirled by a string vertically round the head, without any danger of the water falling out of it. Those parts of the Earth that come successively OPPOSITE to the Moon, perform a much larger circle round the centre of gravity, than the parts immediately UNDER the Moon: hence the waters opposite the Moon are THROWN OFF, as it were, by their centrifugal motion, and rise above the common level, as well as the waters exposed to the Moon’s immediate attraction; thus two tides are produced in 25 hours, opposite to each other; and by the Earth turning through those protuberances, its waters rise and fall. The Sun would produce two small, but similar tides, if the Earth had no Moon; therefore at the full of the Moon the Sun’s centrifugal tide being reinforced by the Moon’s attraction, and the Moon’s centrifugal tide being also assisted by the Sun’s attraction, spring tides take place at the full, as well as at the change, of the Moon. ☞ This Scene also receives collateral assistance, exhibiting and explaining the setting of the tides in all the large oceans and the principal seas of the Earth. Scene 4. _THE SOLAR SYSTEM._ This displays the whole Copernican or Solar System, with every planet and satellite in diurnal and annual motion! With awe and deference I offer this daring but humble transcript of creation! Enough, if one idea can be added, to the ingenuous mind, of the attributes and perfections of the Deity. The SUN, a huge globe of fire (957,942 miles diameter, and consequently a million times as large as our Earth, and intended to give light, heat, and vegetation, to seven primary and at least eighteen secondary worlds) is placed in the centre of the system; and by spots on his disk is discovered to turn on his axis in about 25 of our days. These spots cannot be permanently fixed, because they are frequently altering in their shape, situation, number, &c. tho’ some have supposed they have seen small indentations on the edge of the Sun, as the spots have passed it, and conjectured that a fluid matter surrounded a dark nucleus, which sometimes becoming bare, might occasion the transient appearance and disappearance of the spots.