Greenwich time is exclusively used in Great Britain, and differs from mean local time about eight minutes on the east and about twenty-two and a half minutes on the west. In Sweden the time of the fifteenth degree of east longitude is the standard for all purposes. It differs from mean local time about thirty-six and a half minutes on the east and about sixteen minutes on the west. In the United States the standards recently adopted are used exclusively in cities like Portland, Me., (33,800 inhabitants,) and Atlanta, Ga., (37,400 inhabitants,) of which the local times are, respectively, nineteen minutes and twenty two minutes faster than the standard, and at Omaha, Neb., (30,500 inhabitants,) and Houston, Tex., (16,500 inhabitants,) each twenty-four minutes slower. At Ellsworth, Me., a city of six thousand inhabitants, a change of twenty-six minutes has been made. Nearly eighty-five per cent. of the total number of cities in the United States of over ten thousand inhabitants have adopted the new standard time for all purposes, and it is used upon ninety-seven and a half per cent. of all the miles of railway lines. Let us now consider whether insuperable practical difficulties owing to geographical peculiarities will prevent the adoption of this system throughout the world. A table has been prepared, and accompanies this paper, upon which are designated the several governing meridians and names suggested for the corresponding sectional times. For the use of this table I am indebted to Mr. E. B. Elliott, of this city. On the North American continent, in the United States and Canada, the 75th, 90th, 105th, and 120th west Greenwich meridians now govern time. In Mexico the 105th west meridian is approximately central, except for Yucatan, which is traversed by the 90th. For Guatemala, Salvador, and Costa Rica, the 90th west meridian is approximately central. San Domingo closely approaches and Cuba touches the 75th. In South America--the United States of Columbia, Ecuador, Peru, the western portion of Bolivia, and Chili would use the time of the 75th west meridian, while Venezuela, Guiana, western Brazil, including the Amazon River region, eastern Bolivia, Paraguay, Uruguay, and the Argentine Republic, would be governed by the time of the 60th meridian. In eastern Brazil the 45th west meridian would govern.