38 prevent.the earth from becoming too dry; and water it with refreshing rain. - Pup. Are they productive of no injurious effects? Tut. In some cases they are. It is generally supposed that earthquakes are occasioned by the accidental explosion or inflautulation of nitrous and sulphureous vapours, or by the expansion of wind or vapour, inclosed or pent up in the bowels of the earth. Pup. How high do the clouds extend above the surface of the earth : * Tut. From about half a mile to two miles. Pup. What produces the various figures and colours of the ciouds 2 - Tut. The reflection of the sun occasions the variety of colours which we observe the clouds to take, according to their density and position with respect to that body; and their various forms are produced by the impulse of the winds.
- Pup. How does it happen fhat the general colour of the sky is blue? o
Tut. From the vapours being mixed with air, and which then have the property of reflecting the blue rays, of the sun more abundantly than those of the other primary colours. Pup. What is the natural cause of rain ? Tut. When the air is so full of heavy vapours that it can nō loinger sustaiti thpm, theii 1bese small moist particles run together, and fall down in fine drops, which we call rain. The rain descending in drops is a further manifestation of divine wisdom; for if it fell in strong streams, it would injure the earth, by washing away its fine light mould from the }
