Page:Popular Science Monthly Volume 45.djvu/772

 its most dangerous enemy—early frost. The spring comes late, as the crust of ice on the lake keeps the water and air cold, and retards the opening of the buds until the usual danger of frost is past. The water exerts a similar favorable influence in autumn, by retaining the heat collected during the summer, so that the fruit is protected from early frosts in September. The presence of this stratum of air is shown by the absence of light frosts during late autumn, and by the greenness of the foliage where the



warm breezes from the lake extend. There is a difference of from six to ten degrees between the temperature near the lake and that on the hilltops.

The soil is also another important factor in the successful growing of grapes. The surface of the Lake Keuka hillsides is composed of gravel and shale on calcareous rock. It looks bare, having been washed off by rainstorms and freshets centuries ago. There are places where vegetation is stunted, and where weeds find no great encouragement; and yet the finest Catawba vines flourish in soils that appear little better than gravel beds. You wonder how grapes can grow and sweeten on such ground. The reason is, that in such earth the soil retains the sun's heat long