Colors and sizes vary too much to be a test of age. The scarred base and the sheared neck are the surest sign of age. In all the older forms, the neck was sheared with scissors, leaving it irregular and without finishing band; also, the base always showed a rough, circular scar, left by breaking the bottle away from the rod which held it while the workman was finishing the neck. Smooth and hollow bases were made between 1850 and 1860 by means of an improvement called a "snap" or case, which held the bottle. At the same time, a rim was added to the mouth. The designs were worked out in transparent white, pale blue, sapphire blue, light green, emerald green, olive, brown, opalescent, or claret color. Twenty-nine of these historic flasks bear for ornament some form of the American eagle; nineteen different designs display the head of Washington, and twelve the head of Taylor. Their shapes varied with the passing of time. The very earliest were slender and arched in form, with edges horizontally corrugated; then came in vogue oval shapes, with edges ribbed vertically. The next pattern was almost circular in form, with plain, rounded edges; and at this time some specimens show a color at the mouth. Then appeared the calabash, or decanter form, no longer flattened and shallow, as the others had been, but almost spherical, with edges that showed vertical corrugation, ribbing, or fluting; with long, slender neck, finished with a cap at the top; with smoothly hollowed or hollowed and scarred base. These were superseded by bottles arched in form, deep and flattened, having vertically corrugated edges, a short and broad neck, finished with a round and narrow heading, and a base either scarred or flat. Last of all appeared the modern flask shape, also arched in form, with a broad shoulder, a narrow base, plainly rounded edges, and a return to the flattened and shallow type of the earliest manufactures. The neck had a single or double beading at the top, and the base was either flat or smoothly hollowed. All the Kossuth and Jenny Lind bottles were made about 1850. The Taylor or Taylor and Bragg bottles belong to the period of the Mexican War, and were probably blown in 1848. One of these bears Taylor's historic command, "A little more grape, Captain Bragg," as delivered at the battle of Buena Vista. Another has a portrait of Washington upon one side, and that of Taylor upon the other, with the motto, "Gen. Taylor never surrenders." This shows the circular, canteen shape.