103 Mahogany. 104 Oak 104 Ebony 130 Sulphur. SPECIFIC GRAVITY OF SUBSTANCES. A gallon of water or wine weighs 10 lbs., and this is taken as the basis of the following table: LIQUIDS. Water.. Sea Water.. Dead Sea.. Alcohol.. Olive oil. Wine Urine Cider. Beer... Woman's milk Porter. Emerald Crystal. Indigo. TIMBER. 100 Cork. 103 Poplar 99 Walnut.. 277.5 Diamond 77 | Peat ........... PRECIOUS STONES. 353.0 | Garnet. 406.3 401.1 Ruby.... 428.3 SUNDRIES. 133 Porcelain. 226 134 Stone.. 252 270 183 Granite....... 278 279 .... 203 Glass 289 SELECTED WEIGHTS. Lbs. per Cub. Ft. Cub. Ft. Cub. Ft. The number of asteroids discovered up to present date is 330. A number of these small planets have not been observed since their discovery, and are practically lost. Consequently it is now sometimes a matter of doubt, until the elements have been computed, if the supposed new planet is really new, or only an old one rediscovered. It is supposed that a Centuri, one of the brightest stars of the Southern Hemisphere, is the nearest of the fixed stars to the earth. The researches on its parallax by Henderson and Maclear gave it for its distance from the earth, in round numbers, 20,000,000,000,000 of miles. At the inconceivably rapid rate at which light is propagated through space, it would require three years and three months to reach the earth from this star. SOME GREAT WATERFALLS. Waterfalls occur most frequently in mountainous countries, where the streams from the mountain sides enter the valleys. These mountain waterfalls, however, are generally rather curious and picturesque than grand, the volume of water being in most cases comparatively insignificant, though the height of fall is occasionally very great. Among the leading waterfalls are: Yosemite (3 plunges)... Roraima Falls, Guiana (2 plunges)........ Sutherland Falls, New Zealand (3 plunges) Gavarnie Fall, Pyrenees Staubbach.. Kaieteur Falls, Guiana Tequendama Falls, near Bogota.. Victoria Falls, Zambesi.. Rio Iguassu, southern Brazil.. Shoshone Foyers, highest in Britain (2 plunges). Hay River, Alaska... Niagara LIGHTNING CONDUCTORS. Copper is the best material for conductors. When circumstances are not such as to promote corrosion iron may be used, but of larger dimensions. Its conductivity is about one-fifth that of copper. Copper lightning conductors should be of the following dimensions: Rods 1⁄2" diameter, tubes " diameter, %" thick, or bands 11⁄2" wide, " thick. Iron lightning conductors should be either solid rods 1" diameter, or bands 2" wide, " thick. Lightning conductors afford protection over a circle whose radius equals their height from the ground; formerly considered twice. LATITUDE AND LONGITUDE. A Table showing the number of miles in degree of longitude at each degree of latitude. THE THERMOMETER. The thermometer is an instrument for measuring the heat or temperature of bodies by the regular expansion of mercury or alcohol in a graduated glass tube. Halley proposed the substitution of mercury for alcohol in 1697. The thermometers usually employed are Fahrenheit's, the Centigrade and Reaumur's, the first invented in 1726, and the two others soon afterwards. The following table is interesting as a comparison of the three thermometers: Ice melts at 32°; temperature of globe, 50°; blood heat, 98°; alcohol boils, 1740; water boils, 2129; lead melts, 594°; heat of common fire, 1,140°; brass melts, 2,233; iron melts, 3,479°. To convert one thermometer into another, observe the following rules: To convert Fahrenheit into Centigrade-Deduct 32°, multiply by 5 and divide by 9. To convert Fahrenheit into Reaumur-Deduct 32°, divide by 9 and multiply by 4. To convert Centigrade into Fahrenheit-Multiply by 9, divide by 5 and add 32°. To convert Centigrade into Reaumur- Multiply by 4 and divide by 5. To convert Reaumur into Centigrade-Multiply by 5 and divide by 4. To convert Reaumur into Fahrenheit-Multiply by 9, divide by 4 and add 32°. SUMMER HEAT IN VARIOUS LANDS. The following figures show the extreme summer heat in the various countries of the world: Bengal and the African desert, 150° Fahrenheit; Senegal and Guadaloupe, 130°; Persia, 125°; Calcutta and Central America, 120°; Yuma, Arizona, 118°; Afghanistan and the Arabian desert, and at Umatilla, Oregon, and Poplar River, Montana, 110°; in four places in western and southern United States the temperature has reached 108°; Cape of Good Hope and Utah, 105; Greece, 104°; Arabia, 103°; Montreal, 103°; New York, and at twelve other places in the United States, 102°; Spain, India, China, Jamaica, and at eleven points in the United States, 100°; Sierra Leone, 94°; France, Denmark, St. Petersburg, Shanghai, the Burman Empire, Buenos Ayres, and the Sandwich Islands, 90°; Great Britain, Siam, and Peru, 85°; Portugal, Pekin and Natal, 80°; Siberia, 77°; Australia and Scotland, 75o; Italy, Venezuela and Madeira, 73°; Prussia and New Zealand, 70°; Switzerland and Hungary, 66°; Bavaria, Sweden, Tasmania and Moscow, 65°; Patagonia and the Falkland Isles, 55°; Iceland, 45°; Nova Zembla, 34°. U. 1.-16 1234. 1420. HISTORIC COLD WEATHER. Mediterranean frozen; traffic with carts. 1468. Wine at Antwerp sold in blocks. 1658. Swedish artillery crossed the sound. 1766. Snow knee-deep at Naples. 1789. Fahrenheit thermometer marked 23° below zero at Frankfort, and 36° below at Basle. 1809. Moscow, 48° below zero, greatest cold recorded there; mercury frozen. 1829. Jakoutsk, Siberia, 73° below zero on the 25th of January; greatest cold on record. .1846. December marked 25° below zero at Pontarlier; lowest ever marked in France. 1864. January, Fahrenheit stood at zero in Turin: greatest cold recorded in Italy. Captain Parry, in his Arctic explorations, suffered for some time fifty-one degrees below zero Frost is diminishing in Canada with the increase of population, as shown by the fact that Hudson's Bay was closed from 1828-137, 184 days per annum, and from 1871-'80 only 179 days per annum. EXTREME HEAT IN EUROPE. In 1303 and 1304 the Rhine, Loire and Seine ran dry. The heat in several French provinces during the summer of 1705 was equal to that of a glass furnace. Meat could be cooked by merely exposing it to the sun. Not a soul dare venture out between noon and 4 P.M. In 1718 many shops had to close. The theaters never opened their doors for three months. Not a drop of water fell during six months. In 1773 the thermometer rose to 118 degrees. In 1778 the heat of Bologna was so great that a great many people were stifled. There was not sufficient air for the breath, and people had to take refuge under the ground. In July, 1793, the heat again became intolerable. Vegetables wers burned up, and fruit dried on the trees. The furniture and wood-work in dwellinghouses cracked and split up; meat, exposed, decayed in an hour. HORSE POWER OF STEAM ENGINES. The unit of nominal power for steam engines, or the usual estimate of dynamical effect per minute of a horse, called by engineers a "horse power," is thirty-three thousand pounds at a velocity of one foot per minute, or, the effect of a load of two hundred pounds raised by a horse for eight hours a day, at the rate of two and a half miles per hour, or 150 pounds at the rate of 220 feet per minute. RULE.-Multiply the area of the piston in square inches by the average force of the steam in pounds and by the velocity of the piston in feet per minute; divide the product by thirty-three thousand, and of the quotient equal the effective power. TERMS IN ELECTRICITY. The technical terms used in regard to electricity refer to units of various nature. Thus the unit of capacity is one farad; the unit of activity, one watt; the unit of work, one joule; the unit of quantity, one coulomb; the unit of current, one ampere; the unit of resistance, one ohm; the unit of magnetic field, one gauss; the unit of pressure, one volt; the unit of force, one dyne. The names are mostly derived from the names of men that have been famous in the field of electrical research. Thus Michael Faraday, James Watt and James P. Joule, famous English discoverers, give their names to the first three units mentioned; Charles A. Coulomb and Andre M. Ampère, French inventors, to the two units following; G. S. Ohm and Carl F. Gauss, Germans, name two more units; and the volt is named from the Italian discoverer, Volta. The dyne is derived from the root word of dynamo, itself meaning force. 3,414 3.210 AUSTRALIA AND POLYNESIA. Mount Hercules, Isle of Papua.. Mauna Koa, Hawaii. Mt. Cook. New Zealand. Kinabalu, Borneo Mt. Kosciusko, New South Wales... 7,308 | Scaw Fell Pike CURIOUS FACTS ABOUT FISHES. Following are some curious facts about fishes. While naturalists have generally accepted Cuvier's view that the existence of fishes is silent, emotionless and joyless, recent observations tend to show that many fishes emit vocal sounds. The anabas scandens, the climbing perch of India, quits the water and wanders over banks for considerable distances, and is even said to climb trees and bushes. At Tranquebar, Hindoostan, may be seen the strange spectacle of fish and shell-fish dwelling high on lofty trees. The perch there climbs up tall fan-palms in pursuit of certain shell-fish which form his favorite food. Covered with viscid slime, he glides smoothly over the rough bark. Spines, which he may sheathe and unfold at will, serve him like hands to hang by, and with the aid of side fins and a powerful tail he pushes himself upward. One species of fish, the sticklebacks, are known to build nests. There are several varieties of this fish, all natives of fresh water with one or two exceptions. They are found in the Ottawa River. The cyprinodon is a sightless fish which gropes in the dreary waters of the Mammoth Cave of Kentucky. The blind fish are so sensitive that the sound made by the dropping of a grain of sand on the water will cause them to dart away beyond reach. THE AURORA BOREALIS. Northern lights, or Aurora Borealis, is the name given to the luminous phenomenon which is seen towards the north of the heavens by the inhabitants of the higher latitudes. During the winter of the northern hemisphere, the inhabitants of the arctic zone are without the light of the sun for months together, and their long dreary night is relieved by this beautiful meteor, which occurs with great frequency in those regions. Those who have explored the southern seas have seen the same phenomenon in the direction of the south pole, so that the term Polar Lights might be more appropriate than Northern Lights to designate the aurora. For the phenomenon as seen in the southern hemisphere, the name aurora Australis is used. The appearance of the aurora borealis has been described by a great variety of observers in Northern Europe and in America, all of whom give substantially the same account of the manner in which the phenomenon takes place. |