[Illustration] =RADIO STATIONS.=—Represents various governmental stations. The U. S. naval radio stations operate to various distances. Communication with most of them can be relied upon by all vessels for 100 nautical miles at least. =MAGNETIC VARIATION.=—The lines of equal magnetic variation for every degree for the epoch 1925 are shown by lines of fine dots in black. =OCEAN CURRENTS.=—The yearly average set of the stream and drift currents is shown by small black arrows. =STORM TRACKS.=—The several red lines indicate the individual paths followed by the centers of the more severe cyclonic storms that have occurred during the corresponding month in past years. (See table in another column.) The successive positions of a storm center at Greenwich mean noon are indicated by small circles with their corresponding dates. [Illustration] =PREVAILING WINDS AND CALMS.=—The wind rose, in blue color, in each 5-degree square shows the character of the winds that have prevailed within that square. The wind percentages north of latitude 30° were concentrated upon eight points; south of latitude 30° upon sixteen points. The arrows fly with the wind. The length of the arrow, measured from the center of the circle on the attached scale, gives the number of times in each 100 observations that the wind has blown from or near the given point. The number of feathers shows the average force of the wind on the Beaufort scale. The figure in the center of the circle gives the percentage of calms, light airs, and variable winds. FOR EXAMPLE: The attached wind rose should be read thus: In each 100 hours the wind has averaged as follows: from N. 32 hours, force, 4; from NNE. 20 hours, force 3; from NW, 18 hours, force, 2; calms, light airs, and variables, 30 hours. [Illustration: SCALE OF WIND PERCENTAGES] =7.= NORTH ATLANTIC LANE ROUTES—CANADA In accordance with the North Atlantic Track Agreement, the Hydrographic Office advises that the North Atlantic Lane Routes to Canada shown in full black lines are effective as follows: TRACK “F” From May 16 to the Opening of Belle Isle Route and to November 30 When Not Using the Belle Isle Route =Eastbound.=—Steer from a position 25 miles south of Cape Race on a course 10 miles south of the Great Circle track until approaching Fastnet, Inishtrahull, or 19 miles south of Bishop Rock. =Westbound.=—Steer from Fastnet, Inishtrahull, or 10 miles south of Bishop Rock, on a course 10 miles north of the Great Circle track until approaching Cape Race, then steer a course to pass 10 miles south of Cape Race, thence to the St. Lawrence. TRACK “G” From the Opening of the Strait of Belleisle to November 14 =Eastbound.=—Steer from Belle Isle on a course 10 miles south of the Great Circle track until approaching Fastnet, Inishtrahull, or 10 miles south of Bishop Rock.