Limerick is also the center of a large butter trade and has the biggest condensed milk factory in the kingdom, using the milk of ten thousand cows daily, which is gathered morning and evening by enormous motors that go thundering around the roads like Juggernauts. They look like steam-rollers, and are built the same way with four wheels that have tires more than a foot wide, and they serve a double purpose by rolling the roads daily while they are hauling in the milk. Each of these ponderous vehicles carries a large tank that will hold a hundred gallons of milk and hauls a trailer that carries two tanks of similar size, thus making about three hundred gallons to the load, but it makes noise enough for ten thousand gallons. The big tanks are painted white and the machines are polished like the knockers on the front doors of the Limerick houses. There are three of these machines, which start out at daylight in the morning, and each goes in a different direction, picking up the milk that is left in cans by the farmers at convenient cross-road stations. When the tanks are all filled the Juggernaut comes rumbling into town, making more noise than the railroad train, discharges its load at the condensed milk factory, and then starts out in another direction. Limerick has a population of about forty thousand, which has been reduced from fifty thousand during the last ten or twelve years by emigration to America; and, as we find it the case everywhere, all the young men who can get money enough to pay their steamship fares are emigrating. Many young women go also, and "the best blood of the country is lost to us," one of the priests remarked. The city has not increased in numbers for centuries. It has merely held its own, and some historians contend that it had more population five hundred years ago than it has now. It was founded before the beginning of history.