Soon after the completion of the Monument on Fish Street Hill, by Wren, in 1677, it was used by Hooke and other members of the Royal Society for astronomical purposes, but abandoned on account of the vibrations being too great for the nicety required in their observations. Hence arose _the report that the Monument was unsafe_, which has been revived in our time; “but,” says Elmes, “its scientific construction may bid defiance to the attacks of all but earthquakes for centuries to come.” This vibration in lofty columns is not uncommon. Captain Smythe, in his _Cycle of Celestial Objects_, tells us, that when taking observations on the summit of Pompey’s Pillar, near Alexandria, the mercury was sensibly affected by tremor, although the pillar is a solid. Geology and Paleontology. IDENTITY OF ASTRONOMY AND GEOLOGY. While the Astronomer is studying the form and condition and structure of the planets, in so far as the eye and the telescope can aid him, the Geologist is investigating the form and condition and structure of the planet to which he belongs; and it is from the analogy of the earth’s structure, as thus ascertained, that the astronomer is enabled to form any rational conjecture respecting the nature and constitution of the other planetary bodies. Astronomy and Geology, therefore, constitute the same science--the science of material or inorganic nature. When the astronomer first surveys the _concavity_ of the celestial vault, he finds it studded with luminous bodies differing in magnitude and lustre, some moving to the east and others to the west; while by far the greater number seem fixed in space; and it is the business of astronomers to assign to each of them its proper place and sphere, to determine their true distance from the earth, and to arrange them in systems throughout the regions of sidereal space. In like manner, when the geologist surveys the _convexity_ of his own globe, he finds its solid covering composed of rocks and beds of all shapes and kinds, lying at every possible angle, occupying every possible position, and all of them, generally speaking, at the same distance from the earth’s centre. Every where we see what was deep brought into visible relation with what was superficial--what is old with what is new--what preceded life with what followed it.