The temple or house of the gods was, of course, a single chamber of moderate size with a treasure house behind it, and the gradual development of it from a simple square chamber with one end opened for a door, and adorned with two pillars between the pilasters which formed the ends of the house wall--the doorway _in antis_, to the elaborate peripteral temple with double rows of pillars running round it--all this is to be found in any handbook of ancient art. From the very use of the temple as compared with the private house, it followed that while the temple looked outward, and was meant to show its beauty to those that approached it, the private house looked inward--all its beauties were reserved for the occupants, and care was even taken to prevent any curious observation on the part of the public. But it is only of recent years that the extant ruins have been minutely measured and studied, and now we know that, in addition to building this rectangular house for the god, there were the most elaborate and minute laws observed in the proportions of the various parts, and in the optical corrections of straight lines, which were found to appear curved. This perfection, therefore, of Greek religious architecture was not merely the adoption of a good practical form, and the carrying out of it in precious materials and with clear and competent workmanship. The most delicate adaptation of curves, the most curious and subtle applications of harmonies in lengths and heights, were utilised to produce an effect which all observers have long felt to be the most marvellous in the world.