Page:Polar Exploration - Bruce - 1911.djvu/40

36 water, the amount depending on the solidity of each sheet of icy snow, but possibly one inch might be above water to five inches below. Magnify your roof, magnify your ice covering which has slipped off the roof and floated off into the water, magnify your snowfall of a single night into that of more than a thousand years, make every inch of thickness 100 feet, and you have models on a scale of 1 to 1,200 of Antarctic icebergs, at least as far as shape is concerned. The mode of formation also is somewhat similar to that of the Antarctic icebergs, although probably the great ice-fields that come flowing over extensive stretches of gently undulating or more or less flat land, and even what would be shallow sea were the ice not there, are fed not only by the intermittent falls of snow year after year and by the drift brought from the mountains and inland ice, but also by glaciers which act as feeders to these low-lying ice-fields, and which keep on pushing the whole mass seaward until great flat-topped pieces, exactly similar in shape to the flat-topped snow islands from the roof, float out to sea.

One of these great ice-fields lies to the south of New Zealand, terminating in an ice cliff in the Ross Sea, which is usually known as the Ross Barrier. This great barrier was discovered by Ross in 1840, and was visited