A semicircle is then drawn behind the bowls with a radius of 9 ft.
Three points are given to the bowl that trails the jack over both lines into the semicircle and goes over them itself.
Four conspicuous features of Pyrenean scenery are the absence of great lakes, such as fill the lateral valleys of the Alps; the rarity and great elevation of passes; the large number of the mountain torrents locally called gaves, which often form lofty waterfalls, surpassed in Europe only by those of Scandinavia; and the frequency with which the upper end of a valley assumes the form of a semicircle of precipitous cliffs, locally called a cirque.
Let APB be a semicircle, BT the tangent at B, and APT a line cutting the circle in and BT at T; take a point Q on AT so that AQ always equals PT; then the locus of Q is the cissoid.
The main water-parting of the Peninsula is everywhere near the edge of the table-land on the north, east and south, and hence describes a semicircle with the convexity to the east.