Invention of Balloons, and Progress of Aerostation.. 396 Balloons inflated with Hydrogen Gas Aerial Voyage of Mr. Blanchard and Dr. Jefferies, The Method of filling Air Balloons with Hydrogen Gas ........ 2 UNIVERSAL SCIENCE. CHAPTER I. GEOLOGY. SECTION I. INTRODUCTION. GEOLOGY, (or Geognosy, as the Wernerian Mi- Obs. Of a portion of two of these parts we shall treat in Our object in this chapter, as every where else in this work, In this view, therefore, the division of our sub- Change of Colour from Brown to White in a Native Case of a Child aged Six Months, who swallowed a Luminous or Phosphorescent Animals... Depredations committed by Locusts in Germany. Extract of a Letter from a Gentleman at Breslau, to his Friend in London. August 27, 1754 Microscopic View of Spiders weaving their Webs Sulphate of Zine (White Vitriol) devoured by Spiders 212 Deposition, proving that the same Serpent, or one of the same Species, was seen in 1815 phenomena of nature, which the science of Geology presents. Instruction will thus be blended with amusement, and the acquisition of scientific knowledge be rendered a pastime, not a task, SECTION II. ROCKS AND VEINS. 1. THE stony masses of which the earth is composed, are numerous, and are found laid one above another; so that a rock of one kind of stone is covered by another species of rock, and this by a third, and so on. In this superposition of rocks, it has been observed, that their situation is by no means arbitrary; each occupies a determinate place, so that they follow one another in regular order from the deepest part of the earth's crust which has been examined, to the very surface. Thus there are two things respecting rocks which claim our attention; namely, their composition, and their relative situation. But besides the rocks which constitute almost the whole of the earth's crust, there are masses to be considered traversing the rocks in a different direction, and known by the name of veins, as if the rocks had split asunder in different places from top to bottom, and the chasm had been afterwards filled up with the matter which constitutes the vein. Thus it appears, that the subject naturally divides itself into three parts; 1. The structure of rocks; 2. The situation of rocks; 3. Veins; and these shall form the subject of the three following sections. SECTION III. OF THE STRUCTURE OF ROCKS. 2. Rocks may be divided into two classes; viz. |