NEW r. LAWSENOE. ���715 ���The specifications next describe the invention as foUows ! The iAention consista in the use of successive layers of roofing felt, asphaltic roofing cernent, associated with a layer of concrete or hydraulio cernent, combined with gravel Or other layers of equivalent material, applied as hereinafter more fully described. �This description would seem intended to convey the idea that a layer of concrete or hydraulic cernent, combined "with gravel, was one of the essential features of the invention. But this idea is dispelled by a subsequent statement that the employment of a layer of concrete is in ail cases optional. It -would seem, too, from this description, that the protecting wall or bulwark of mason work or other niaterial suitable to aid in resisting water pressure, which is subsequently men- tioned, was not part of the invention. But the subsequent portions of the specifications clearly point to such protecting wall as an essential feature of the invention, and these por- tions of the specifications may be considered as referred to by the words "applied as hereinafter more fùlly described," and in the description of the invention, and so intended to form part of that description. The specifications, after having thus described the invention, refer to an accompanying drawing of a cellar, and give a description of the method of construct- ing, first, the bottom, and then the walls of a cellar, accord- ing to the plaintifE's process ; but pains are taken to bave it understood that the scope of the patent is not limited to the construction of cellars, for the description of a cellar, which is given by way of illustration, is prefaced by the statement : "My invention is not limited to the particular combina tion of the materials heretofore mentioned and used, as hereinafter setforth;" and is followed by the statement: "As already stated, I do not limit myself to the particular combination, and the application of such materials as hereinafter de- scribed. The especial and most useful feature in my inven- tion is the use of the layer of roofing felt and the layers of asphaltic or roofing cement." �The claim is in the following language : "In sanitary ■water-proof cellars, cisterns, vaults, reservoirs, and similar ����
