forepart of the storm. In this case they are usually more abundant, their outline is very ragged, and they generally blend into a white, far-reaching cloud-bank. Second order, Cumulus, well known as "cotton-bales," or "thunder heads"; they are of a hemispherical form, with horizontal base. When they appear during the heat of the day and pass away in the evening, continued fair weather may be expected. When they increase with rapidity, sink into the lower part of the atmosphere, and remain as the evening approaches, rain is at hand. If loose patches appear thrown out from their surfaces, showers may be expected. Third order, Stratus. These appear as a continuous layer of widely extended sheet of cloud, at a lower level than the Cumulus, their lower surface often resting on the earth. Barometer.-In using the barometer it should be noticed whether it be greatly above or below the mean height, and the rapidity of its rise or fall. If it be higher and steady, continued fair, though not cloudless, weather may be expected. If it be lower and falling, rain, or at least damp, cloudy weather is at hand. A rapid rise or fall (greater than 0.01 inch per hour) indicates continued unsettled weather and much wind. Cloud Indications.-Most people know that a fall in the barometer indicates the approach of a storm, and a high barometer indicates fair weather; but more than this may, according to M. Flammarion, be learned from the mercury column. When clouds are to be seen moving in a line, whatever may be the height of the barometer, it may be taken as certain that a depression or storm centre exists in a direction which may be readily ascertained by facing in the direction in which the clouds are moving, and extending the left hand. At sea it is often possible for a captain, after finding in what direction the most violent part of a storm lies, to steer away from it, and soon bring his vessel into pleasant weather. to the distance and seriousness of the storm, something may be learned from the velocity with which the procession of clouds move; a severe and near storm being always indicated by a swift cloud movement and a high barometer. RULES FOR FORETELLING WEATHER. (Adapted for use with Aneroid Barometers.) A Rising Barometer.-A rapid rise indicates unsettled weather. A gradual rise indicates settled weather. A rise with dry air and cold increasing in summer indicates wind from the northward; and if rain has fallen, better weather may be expected. A rise with moist air and a low temperature indicates wind and rain from the northward. A rise with southerly winds indicates fine weather. A Steady Barometer.-With dry air and seasonable temperature indicates a continuance of very fine weather. A Falling Barometer.-A rapid fall indicates stormy weather. A rapid fall with westerly wind indicates stormy weather from the northward. A fall with a northerly wind indicates storm, with rain and hail in summer, and snow in winter. A fall with increased moisture in the air, and heat increasing, indicates wind and rain from the southward. A fall with dry air and cold increasing in winter indicates snow. A fall after very calm and warm weather indicates rain with squally weather. The barometer rises for northerly winds, including from northwest by north to the eastward for dry, or less wet weather, for less wind, or for more than one of these changes, except on a few occasions, when rain, hail, or snow comes from the northward with strong wind. The barometer falls for southerly wind, including from southeast by south to the westward, for wet weather, for stronger wind or for more than one of these changes, except on a few occasions, when moderate wind, with rain or snow, comes from the northward. STORM SIGNALS OF U. S. WEATHER BUREAU. Storm Signals.-A red flag with a black centre indicates that a storm of marked violence is expected. The pennants displayed with the flags indicate the direction of the wind; red, easterly (from northeast to south); white, westerly (from southwest to north). The pennant above the flag indicates that the wind is expected to blow from the northerly quadrants; below, from the southerly quadrants. By night a red light indicates easterly winds, and a white light above a red light westerly winds. Information Signal.-Red or white pennant displayed alone. When displayed at stations on the Atlantic, Pacific, and Gulf coasts indicates that the local observer has received information from the Central Office of a storm covering a limited area, dangerous only for vessels about to sail to certain points, and serves as a notification to shipmasters that information will be given them upon application to the local observer. Only the red pennant is displayed on the coasts. No night information or hurricane signals are displayed. Hurricane Signal.-Two red flags with black centres, displayed one above the other, indicate the expected approach of tropical hurricanes, and also of those extremely severe and dangerous storms which occasionally move across the Lakes and Northern Atlantic coast. RULES FOR HURRICANES. The September chart of 1893 of the Hydrographic Bureau gives the following rules for the benefit of mariners, yachtmen and others when overtaken by a hurri cane: Rule 1.-If the squalls freshen without any shift of wind, you are on or near the storm track; heave-to on the starboard tack and watch for some indications of a shift, observing the low clouds particularly; if the barometer fall decidedly (say half an inch) without any shift, and if wind and sea permit, run off with the wind on the starboard quarter and keep your compass course. Rule 2.-If the wind shift to the right, you are in the right of the storm track, in the dangerous semicircle; put the ship on the starboard tack and make as much headway as possible until obliged to lie-to (starboard tack). Rule 3.-If the wind shift to the left you are to the left of the storm track, in the navigable semicircle; bring the wind on the starboard quarter and keep your compass course; if obliged to lie-to, do so on the port tack. Always lie-to on the coming-up tack. Use oil to prevent heavy seas from breaking on board your vessel. DISTANCES AT SEA. The earth being round, its convexity limits the vision even on a level like the sea. The line of vision on the seashore of a man of ordinary height, say six feet, would be intercepted by the horizon at 3.24 miles. If he were looking at an object 44 feet in height, say a flag on a masthead, the flag would seem to be on the horizon if it were 9.35 miles distant. In this case add the height of the object, 44 feet, to the height of the eye from the ground, 6 feet 50 feet, and find the corresponding distance in the list below. A carrier pigeon at a mile above the earth would only command a field of 96 miles in radius. = This table shows the distance from sea-level at which objects are visible at different elevations. LENGTH OF DEGREES OF LONGITUDE. A degree of longitude at 1° of latitude 60 miles A degree of longitude at 10° of latitude 59 miles, about A degree of longitude at 20° of latitude=561⁄2 miles, about A SHIP'S SPEED. A ship at 1 knot per hour goes about 1.69 feet per second. A ship at 10 knots per hour goes about 16.89 feet per second. A ship at 15 knots per hour goes about 25.33 feet per second. A ship at 16 knots per hour goes about 27.02 feet per second. A ship at 17 knots per hour goes about 28.71 feet per second. A ship at 18 knots per hour goes about 50.4 feet per second. A ship at 19 knots per hour goes about 32.09 feet per second. A ship at 20 knots per hour goes about 33.78 feet per second. A ship at 21 knots per hour goes about 35.47 feet per second. |