M'Keesport, a borough of Pennsylvania, on the Monongahela River, at the mouth of the Youghiogheny, 15 miles SE. of Pittsburgh. It has flour, saw, and rolling mills, tubing factories, glass-works, a distillery, etc. Natural gas is used. Pop. (1880) 8212 ; (1900) 34,227.
Mackenzie River, in North America, has its origin as the Athabasca (q.v.), in a Rocky Mountain lake in British Columbia, flows over 600 miles to Lake Athabasca, and 240 as the Slave River to Great Slave Lake (q.v.). As the Mackenzie River, it now conveys the waters of the Great Slave Lake to the Arctic Ocean at Mackenzie Bay, after a final course which is reckoned at 1045 miles, making a total river-system of nearly 2000 miles. Its great tributaries, the Liard and the Peace and Athabasca rivers, drain an immense fertile country, with abundance of petroleum, and some coal and lignite. It was discovered by Sir Alexander Mackenzie in 1789. The Mackenzie district has an area of 562,182 sq. m., and the population does not exceed 5250. It is largely forested, and the climate is excessively severe in winter.
Mackinley, Mount, the highest mountain in North America, is in Alaska, in lat. 63° 4' N. and long. 151° W., and is 20,464 feet high.
Macon (Md-kong; Matisco of Caesar), the capital of the French dep. of Saone-et-Loire, on the right bank of the Saone, 41 miles by rail N. of Lyons. A dull, moflernised place, it has a twelve-arch bridge, with a view of Mont Blanc ; a fragment of an old cathedral, demolished at the Revolution ; the fine Romanesque church of St Pierre (rebuilt 1866); and a statue of Lamartine, who was born here. It trades largely in wines known as Macon, like but lighter than Burgundy, and manufactures watches, brass, faience, etc. Pop. 18,497.
Macon (May'kon), capital of Bibb county, Georgia, on the Ocmulgee, stands among forest-clad hills, at the head of navigation, 103 miles SSE. of Atlanta. It is the seat of Mercer University (Baptist) and a R. C. college, and has foundries, flour and lumber mills, cotton-factories, etc. Pop. 25,300.
Macquarie Land, a grassy island, 20 miles long, in the Antarctic Ocean, in 54° 30' S. lat. and 158° 50' E. long. It was discovered in 1811.
Macroom, a market-town on the Sullane, 25 miles W. of Cork. Pop. 3020.
Madeira, the great affluent of the Amazon, has its origin in the confluence of the Mamore and Guapore, at about 12° S. lat., the Beni joining 110 miles lower down. The river then flows north-east to the Amazon, the distance from its mouth to its first falls being 578 miles ; above this point navigation is broken by a series of nineteen falls, rapids, and cataracts.