And how admirably did the obelisk lend itself to its symbolical purposes! There was a most wonderful harmony between the idea and the object which expressed it. Being composed of the most durable of all materials, the hard indestructible granite, the eternal sun was thus fittingly represented by an object that lifts its stern finger in unchangeable defiance of the vicissitudes of the seasons and the ages. Its highly polished surface and rich rosy red colour, its sharply defined lines and narrow proportions, combined with its immense height, suggested the brilliancy and hue and form of a pencil of light. Its tall red column flashing in the strong morning radiance, like a tongue of flame mounting up to its source in the solar fire, or like a ray of the halo that rises up on the low horizon of the Libyan desert, when the dawn has crimsoned all the eastern heavens, might thus well be selected as the most suitable object to bring the invisible sun-god within the ken of human vision and the range of human worship. The poetical imagination may detect a significance even in the difference between the material used in the construction of the obelisk, and that used in the construction of the pyramid, though this may not have been designed by the makers. The obelisks are all formed of granite, the foundation-stone of the globe, belonging to the oldest azoic formation, which laid down the first basis for the appearing of life. The pyramids were nearly all made of nummulitic limestone composed of the remains of organic life; a material which belonged to the latest geologic ages, when whole generations and different platforms of life had come and gone. Thus significantly does the obelisk of granite suggest by its material as by its form the origin of life, as the pyramid suggests by its material and form the extinction of life.