delivered the opinion of the Court:
This is an appeal from the rejection of an application for a patent having the following eight claims:
“1. The method of storing and utilizing energy which consists in, first, placing a body of liquid at a point of high negative gravitational potential with reference to the surface of the earth, thereby requiring the expenditure of energy to raise it to the surface of the earth; second, generating energy suitable for elevating said body of liquid; third, employing said energy to transfer said body of liquid to a point of less negative gravitational potential; fourth, temporarily storing said liquid at said point of less negative gravitational potential, thereby storing the energy of said liquid and eliminating the use of structure-supported tanks for such storage; and, fifth, subsequently permitting said liquid to flow back to said point of high negative gravitational potential, and simultaneously transforming the gravitationally stored energy into kinetic energy.
*23“2. The method of storing and utilizing energy which consists in, first, placing a body of liquid at a point of high negative gravitational potential with reference to the surface of the earth, thereby requiring' the expenditure of energy to raise it to the surface of the earth; second, generating energy suitable for elevating said body of liquid; third, transferring said body of liquid to a point of substantially zero gravitational potential by the action of said generated energy; fourth, temporarily storing said liquid at said point of substantially zero gravitational potential, thereby storing up a very large amount of energy per unit mass of said liquid, eliminating the use of structure-supported tanks for such storage and reducing the cost of such storage per horse power to less than the cost of generation; and, fifth, subsequently permitting the liquid to flow back to said point of high negative gravitational potential and simultaneously transforming the gravitationally stored energy into kinetic energy.
“3. The method of storing and utilizing energy which consists in, first, placing a body of liquid at a point of high negative gravitational potential with reference to the surface of the earth, thereby requiring the expenditure of energy to raise it to the surface of the earth; second, generating energy suitable for elevating said body of liquid; third, employing said energy to transfer said body of liquid to a point of less negative gravitational potential; fourth, temporarily storing said liquid at said point of less negative gravitational potential, thereby storing the energy of said liquid and eliminating the use of structure-supported tanks for such storage; and, fifth, subsequently permitting said liquid to flow back to said point of high negative gravitational potential, and simultaneously transforming the gravitationally-stored, energy into electrical energy.
“4. The method of storing and utilizing energy which consists in, first, placing a body of liquid at a point of high negative gravitational potential with reference to the surface of the earth, thereby requiring the expenditure of energy to raise it to the surface of the earth; second, generating energy suitable for elevating said body of liquid; third, transferring said body of *24liquid to a point of substantially zero gravitational potential by tbe action of said generated energy; fourth, temporarily storing said liquid at said point of substantially zero gravitational potential, thereby storing up a very large amount of energy per unit mass of said liquid, eliminating the use of structure supported tanks for such storage and reducing the cost of such storage per horse power to less than the cost of generation; and fifth, subsequently permitting the liquid to flow back to said point of high negative gravitational potential and simultaneously transforming the gravitationally stored energy into electrical energy.
“5. The method of storing and utilizing energy which consists in, first, placing a body of liquid at a point of high negative gravitational potential with reference to the surface of the earth, thereby requiring the expenditure of energy to raise it to the surface of the earth; second, generating energy suitable .for elevating said body of liquid; third, employing said energy to transfer said body of liquid to a point of less negative gravitational potential; fourth, temporarily storing said liquid at said point of less negative gravitational potential, thereby storing the energy of said liquid and eliminating the use of structure-supported tanks for such storage; fifth, subsequently permitting said liquid to flow back to said point of high negative gravitational potential and simultaneously transforming the gravitationally-stored energy into electrical energy; and finally, transmitting said electrical energy to a distance and there utilizing the energy originally stored.
“6. The method of storing and utilizing energy which consists in, first, placing a body of liquid at a point of high negative gravitational potential with reference to the surface of the earth, thereby requiring the expenditure of energy to raise, it to the surface of the earth; second, generating by a given source electrical energy suitable for elevating said body of liquid; third, employing said electrical energy to transfer said body of liquid to a point of less negative gravitational potential; fourth, temporarily storing said liquid at said point of less negative gravitational potential, thereby storing the energy of said *25liquid and eliminating the use of structure-supported tanks for such storage; fifth, subsequently permitting the liquid to flow back to said point of high negative gravitational potential and simultaneously transforming the gravitationally stored energy into electrical energy; and finally, supplementing the gravitationally produced electrical energy by the electrical energy directly produced by said given source.
“7. The method of storing and utilizing energy which consists in, first, placing a body of liquid in a chamber excavated below the surface of the earth and at a point of high negative gravitational potential, thereby heating the liquid in winter and cooling the same in summer, whereby freezing in winter and evaporation in summer are prevented; second, generating energy suitable for elevating said body of liquid; third, employing said energy to transfer said body of liquid to a point of less negative gravitational potential; fourth, temporarily storing said liquid at said point of less negative gravitational potential, thereby storing the energy of said liquid and eliminating the use of structure-supported tanks for such storage; and, fifth, subsequently permitting said liquid to flow back to said point of high negative gravitational potential, and simultaneously transforming the gravitationally-stored energy into kinetic energy.
“8. The method of storing and utilizing energy which consists in first placing a body of liquid in a chamber excavated below the surface of the earth at a point of high negative gravitational potential, thereby heating the liquid in winter and cooling it in summer, whereby freezing in winter and evaporation in summer are prevented; second, generating energy suitable for elevating said body of liquid; third, transferring said body of liquid to a point of substantially zero gravitational potential by the action of said generated energy; fourth, temporarily storing said liquid at said point of substantially zero potential, thereby storing up a very large amount of energy per unit mass of said liquid, eliminating the use of structure-supported tanks for such storage and reducing the cost of such storage per horse power to less than the cost of generation; and, fifth, subse*26quently permitting the liquid to flow back to said point of high negative gravitational potential and simultaneously transforming the gravitationally stored energy into kinetic energy.”
The application was filed June 7, 1907; the rejection was upon reference to British patents to Hillyard, May 9, 1884, to Maxim March 21, 1882, and to Fox June 22, 1905, and also to a decision of this court on a previous appeal of the same party in an apparatus application. See Re Fessenden, 36 App. D. C. 425.
The patent to Hillyard shows á like system in which the lower reservoir is sunk in the earth and the upper one is elevated upon supports.
The Maxim patent shows the idea of using a difference of surface levels to produce the necessary head to use water pressure for generating electric current.
The patent to Fox shows the use of a natural elevation for storing energy. Water is accumulated during normal operation, and energy is restored to the system by means of a turbo-generator when the ordinary source fails.
What the references do not show is the location of the lower reservoir in the deep pit in the earth.
The Examiners in Chief were of the opinion that claims 1 to 6 are not limited to the use of such a pit, and question whether claims 6 and 7, which called for such a pit, would not read on claim 3.
As the Patent Commissioner stated, “assuming, however, that the claims are all limited to the location of the lower reservoir in a deep pit, it adds nothing to their patentability, for it is a purely structural idea, and not a process idea. The cycle of operations and the relation of cause and effect in the various steps of the process are exactly the same, whatever the nature of the supports for the water tanks, and whatever their location relative to a selected part of the earth’s surface. The true process disclosed in this case is precisely the process involved in each of the British patents cited.” He further stated: “The limitation to the structure for performing the process is out of place in these claims. It malíes them- equivalents in substance *27to the apparatus claims of applicant’s companion case, in which such limitations were properly inserted. That case went to the court of appeals, and the corresponding claims were held unpatentable over the same references as are filed herein. The patentability of the idea of locating the lower reservoir for such a system at the bottom of a deep pit having been adjudicated in the apparatus case, to which it properly pertained, and decided against applicant, he cannot now obtain a patent on the same idea by cleverly mingling it with claims to the process inherent in all such systems.”
We agree with both conclusions of the Commissioner. The claims are properly apparatus claims which were refused in the application in the former case. They undertook to convert into a method what is the simple function of the apparatus in that case. Re Fessenden, 36 App. D. C. 425.
The decision is affirmed, and this decision will be certified to the Commissioner of Patents. Affirmed.