3.  A great and honourable man was Abraham, but only great in comparison with men; and when he came before God, then speaking the truth candidly he saith, I am earth and ashes Gen. xviii. 27..  He did not say ‘earth,’ and then cease, lest he should call himself by the name of that great element; but he added ‘and ashes,’ that he might represent his perishable and frail nature.  Is there anything, he saith, smaller or lighter than ashes?  For take, saith he, the comparison of ashes to a house, of a house to a city, a city to a province, a province to the Roman Empire, and the Roman Empire to the whole earth and all its bounds, and the whole earth to the heaven in which it is embosomed;—the earth, which bears the same proportion to the heaven as the centre to the whole circumference of a wheel, for the earth is no more than this in comparison with the heaven The opinion of Aristarchus of Samos, as stated by Archimedes (Arenarius, p. 320, Oxon), was that the sphere of the fixed stars was so large, that it bore to the earth’s orbit the same proportion as a sphere to its centre, or more correctly (as Archimedes explains) the same proportion as the earth’s orbit round the sun to the earth itself.  Compare Cat. xv. 24.:  consider then that this first heaven which is seen is less than the second, and the second than the third, for so far Scripture has named them, not that they are only so many, but because it was expedient for us to know so many only.  And when in thought thou hast surveyed all the heavens, not yet will even the heavens be able to praise God as He is, nay, not if they should resound with a voice louder than thunder.  But if these great vaults of the heavens cannot worthily sing God’s praise, when shall ‘earth and ashes,’ the smallest and least of things existing, be able to send up a worthy hymn of praise to God, or worthily to speak of God, that sitteth upon the circle of the earth, and holdeth the inhabitants thereof as grasshoppers Is. xl. 22..