King Percolator, as Applied to a Hotel or Restaurant Urn

Among later developments of the genuine percolator principle that have attracted attention in this country, mention should be made of the Phylax coffee maker, and the Galt pot.

In 1914–16, there was a revival of interest in the United States in the double glass-globe method of making coffee, introduced into France as "double glass balloons" in the first half of the nineteenth century. American ingenuity produced several clever adaptations, and several notable filter improvements. Advertising developed a great demand for glass percolators, as they were first called; but although five attained considerable prominence, only two survived and, at this writing, are still being manufactured. Both are double glass-globe filters employing a spirit lamp, gas, or electricity as heating agents.

Three Types of American Coffee Makers in Operation
Left, Blanke's Cloth Filter—Center, Phylax—Right, Galt Vacuum device

Within the last few years, it has become the fashion to obtain patents in the United States on "the art of brewing coffee", or the "art of making coffee". Instances are the patents issued to Messrs. Calkin and Muller. In the Calkin patent (the Phylax device illustrated at the top of this page) the "art" consists in controlling the flow of the boiling water by means of the number and spacing of the holes in the water-spreader, so as to restrict the volume and the speed, to effect a quick initial extraction; and then, by means of a new spacing of holes in the infuser, retarding the drip "to attain a prolonged extraction of the tannin and other elements of slow extraction and combining the liquids obtained during the initial and subsequent stages of the brew for attaining a balanced liquid extract."