delivered tbe opinion of tbe Court:

Tbe appellant, Daniel B. Adams, bas appealed from tbe decision of tbe Commissioner of Patents rejecting three claims of bis application for a patent for an improvement in automatic stopping device for engines and tbe like.

Tbe rejected claims are numbered 1, 6, and Y.

Claim 1 reads as follows:

“1. In a stopping device, for engines and tbe like, tbe combination witb a jacketed engine cylinder, and means for supplying a cooling fluid to tbe jacket of a thermostat located in proximity to tbe jacket, and engine-stopping means controlled by tbe thermostat and arranged to be operated thereby to stop tbe engine.”

Claim 6 has been abandoned, and claim Y covers the same combination as claim 1, but adding thereto tbe element of an alarm operated by tbe same thermostat.

Tbe invention is intended for operation in connection witb tbe water-jacketed cylinder of a gas engine. A thermostat is located in or upon tbe jacket, and connected witb tbe fuel supply and tbe sparking device so as to stop tbe engine when tbe temperature shall have risen to a certain point beyond which danger lies. Tbe addition of claim Y is for a connection that rings an alarm bell before stopping tbe engine.

Tbe tribunals of tbe Patent Office were unanimous in denying tbe aforementioned claims. Tbe Commissioner cites several existing patents showing tbe state of tbe particular art in consideration of which be denied tbe claim of invention made by tbe applicant. Without restating tbe references in bis decision, -it is sufficient to say that one of tbe former patents discloses means for cutting off tbe fuel supply and stopping engines of tbe kind upon a failure, from any cause, of tbe supply of cooling water in tbe cylinder jacket. Others show a thermostat connected witb .a gas-engine cylinder to cut off tbe supply of gaseous fuel, and open tbe supply of liquid fuel when a certain temperature is *277reached. And upon further increase of temperature the thermostat causes an additional supply of water. The Commissioner then proceeds to say:

“It is a matter, of common knowledge that thermostats are in general use in many arts for cutting off the supply of heating medium when the temperature rises above a desired point. The question presented is whether stopping an engine by a rise in the temperature thereof is such a new result as to confer the quality of invention upon the means by which it is secured, namely, the combination of an engine-stopping device and a thermostat. It must be held that the decision of the Examiners-in-Chief in the negative was correct.”

It is the settled rule of this court that unanimity of decision in the Patent Office imposes upon an appellant the burden of showing very clearly that error was committed in the final decision of the Commissioner in order to warrant its reversal. Notwithstanding the able argument on behalf of the appellant, we are of the opinion that this burden has not been overcome. In view of the common use of the well-known thermostat in this and other devices, we cannot agree that in the combination of the claims it is made to perform other than its usual function, or to co-operate in producing a new and useful result that rises to the dignity of invention.

The decision must therefore be affirmed with direction to certify the proceedings in this court to the Commissioner of Patents. It is so ordered. Affirmed.