At first the panes were very small, and many were required in large windows, but as glass making advanced, the prevailing size was successively enlarged from about five by seven inches to six by eight, seven by nine, eight by ten, and nine by twelve. As the size of individual panes of glass was increased, their number in each sash was in some instances correspondingly decreased, although oftener larger sashes with the same number of panes resulted. Philadelphia architects always manifested a keen appreciation of the value of scale imparted by the sash bar divisions of their windows, and for that reason small-paned sashes never ceased to be popular. Although numerous variations exist, the custom of having an equal number of panes in both upper and lower sashes predominated. Six, nine and twelve-paned sashes forming twelve, eighteen and twenty-four paned windows were all common throughout the Colonial period. Twelve-paned sashes were used chiefly in public buildings and the larger private mansions, six-paned sashes in houses of moderate size. While there are several notable instances of nine-paned upper and lower sashes, particularly Hope Lodge, Cedar Grove in Harrowgate, Northern Liberties, and the Wharton house at Number 336 Spruce Street, this arrangement frequently, although not always, resulted in a window rather too high and narrow to be pleasing in proportion. A comparison of the accompanying photographs of the window of a Combes Alley house with that of a house at Number 128 Race Street well illustrates the point. Sometimes, where used on the lower story, six-paned upper and lower sashes are found in the windows of the second story. Waynesborough, in Easttown Township, Chester County, not far from Philadelphia, is a well-known case in point. Grumblethorpe presents the anomalous reverse arrangement of six-paned sashes on the first story and nine-paned sashes on the second story. Still oftener six-and nine-paned sashes were combined in the same window, the larger sash being sometimes the upper and again the lower. Bartram House and the Johnson house are instances of nine-paned upper and lower sashes on the first story and nine-paned lower and six-paned upper sashes on the second story. Greame Park in Horsham, Montgomery County, not far from Philadelphia, has nine-paned upper and lower sashes on the lower story and twelve-paned lower and nine-paned upper on the second floor. Penn's house in Fairmount Park and Glen Fern are instances of nine-paned lower and six-paned upper sashes on the first story and six-paned upper and lower sashes on the second story. Solitude and the Blackwell house, Number 224 Pine Street, exemplify the reverse arrangement of nine-paned upper and six-paned lower sashes on both stories.