783. _Why would a piece of lead tied to a string, and let down from a church steeple, incline a little from the perpendicular towards the church?_ Because the _masses of stone_ of which the church is built would _attract the lead_. 784. _How can man weigh the earth?_ By observing what is called the _deflection_ of small bodies _when brought within given distances of larger bodies_, the degree of attraction _exercised by the large body upon the smaller one_ becomes known. This attraction of the _large body_ exercised over the _smaller body_ is an opposing influence, _acting against the earth's attraction of the small body_, which is drawn out of its course: it constitutes a _natural balance between the influence of the earth and another body, acting in opposition to it_. Founded upon these, and some other data, man can weigh the earth, and give a morally certain result! _Deflection_.--The act of turning aside. 785. _How can man weigh the planets?_ The planets exercise as certain an influence upon each other _as do two pieces of wood floating upon a basin of water_. As the planetary bodies fly through their prescribed orbits, _and approach nearer to, or travel further from, each other_, they are observed to _deviate_ from that course which they must have pursued _but for the increase or the decrease of some influence of attraction_. By making observations _at various times_, and by comparing _a number of results_, it is possible _to weigh any planetary body, however vast, or however distant_. [Verse: "Is not God in the height of the heaven? and behold the height of the stars, how high they are?"--JOB XII.] 786. _How can man measure the distances of the planets?_ By making observations at _different seasons of the year_, when the earth is in _opposite positions in her orbit_; and by recording, by _instruments constructed with the greatest nicety_, the _angle of sight_, at which the planetary body is viewed; by noticing, also, _the various eclipses_, and estimating _how long the first light after an eclipse has ceased_ reaches the earth, it is possible to estimate the _distances_ of heavenly bodies, _no matter how far in the depths of the universe those orbs may be_. 787. _What are the opinions founded upon estimates respecting the magnitude of the sun?_ The _diameter_ of the _sun_ is 770,800 geographical miles, or 112 times greater than the diameter of the earth; its _volume_ is 1,407,124 times that of the earth, and 600 times greater than _all the planets together_; its _mass_ is 359,551 times greater than the earth; and 738 times greater than that of _all the planets_. A _single spot_ seen upon its surface has been estimated to extend over 77,000 miles in diameter, and a _cluster of spots_ have been estimated to include an area of 3,780,000 miles. 788. _What is the weight of the earth?_ The earth has a _circumference_ of 25,000 miles, and is estimated to _weigh_ 1,256,195,670,000,000,000,000,000 tons.