This is an action of tort, in the nature of trover, to recover the value of a steam engine and boiler. To maintain this action, the plaintiff must prove property in himself, and a conversion by the defendant.

Upon the facts stated, the «court are of opinion that the engine and boiler, having been erected on the premises of Josiah Richardson, of which he was then the owner in fee, subject to several mortgages, became annexed to the freehold. Winslow v. Merchants’ Ins. Co. 4 Met. 306. This real estate comprised a manufactory occupied and carried on by said Richardson, and the engine was erected to furnish power for such manufactory The steam boiler was permanently set in brick work, and could not be removed without taking down the brick work, and the *538engine was permanently annexed- to the buildings. This nermanent annexation of the engine and boiler to the freehold, de facto, rendered them part of the realty; and his agreement with the builders to give them a mortgage thereon as personal property, as against all those who took title to the estate in fee, was inoperative and void. No title to these articles passed as personal property to the mortgagees, which they could assert against a third party. The engine and boiler thus remained part of the realty till Josiah Richardson became insolvent, and the estate passed to his assignees, subject to the right of the mortgagees of the real estate; it was rightly sold by order of the commissioner, on their petition, and a good title passed to Harlow, the purchaser. He afterwards severed them, and thus reconverted them into personal property, as he lawfully might, and sold them to the defendant, who thereby took a good title.

The evidence of usage was rightly rejected ; it could not be eceived to control the operation of law, arising from the actual annexation of the engine and boiler to the freehold. If it be said, it might have tended to show the intent of the parties; the answer is, that the intent of the parties was manifest enough from the agreement of the parties and the mortgage. But the difficulty was, (by mistake of the law, no doubt,) that this inten tion was one which the law could not carry into effect, that of hypothecating a portion of the realty, as personal property, with out severance.

The fact, that Harlow had full knowledge of the history of the mortgage, did not impair his right to be a purchaser.

It is to be observed, as a fact important to the present case, that the engine and boiler were purchased and set up in the factory by one who himself owned the freehold. Had they been so bought and placed by a tenant on leased premises, the case might have presented a different question.

Judgment for the defendant.