delivered the opinion of the coui’t.
Both of the parties claim under T. M. Knox, and the question is whether Knox, by his three deeds to Deaver, conveyed all his interest in the Petit tract, so that there was nothing left on which his subsequent deed to Dorwart could operate.
The northern line of the Petit tract is coincident with the southern line of the Lami tract, and the first portion of the land which Knox acquired was a strip of fifty-two feet, taken from the northern side and running the whole length of it, which was bounded on the north by the Lami tract claimed by Cerré ; and, although there is some dispute as to Knox’s southern line, all the parties concede that his northern boundary was the southern boundary of the Lami or Cerré tract.
The first deed of Knox to Deaver, dated January 7, 1843, conveys, by a very clear description, all the land he owned in the tract west of a point on his northern line distant twelve chains and forty links from Carondelet avenue. The calls of the deed are “ commencing at a point in Knox’s northern boundary line, being distant, &c., thence, with said Knox’s northern bou/ndary line, north, seventy and one-quarter degrees west, seven chains and one link, to Knox’s north-western corner ; thence,” <fcc. After making this deed, he had remaining the eastern portion of the tract fronting 218 feet six inches on Carondelet avenue, and by his deed to Deaver *407of January 23, 1844, be conveyed tlie southern half of the residue fronting one hundred and nine feet three inches on Carondelet avenue. In this deed Knox assumed his lower line to be further south than it really was, but it is manifest that he intended to convey half of all he had. The portion left, after satisfying the two deeds already mentioned, was a piece bounded north by the Lami or Cerré tract, west by a part of the land first sold to Deaver, south by the part last sold, and east by Carondelet avenue; and this part he intended to convey by his third deed dated March 25,1844. The call in the description is “ beginning at the south corner of said Deaver’s lot (on Carondelet avenue), thence north 109 feet three inches to lot of one Cerré, being school lands, thence west along said Cerré’s line to a lot of said Deaver; thence south,” Ac. It is impossible to reach Cerré’s line without going to Knox’s extreme northern line, and as that line is so described as to be regarded as a monument, it must prevail over distance, which is most uncertain; for it is a familiar rule that the least certainty of description in deeds must yield to the greater certainty.
The legal construction of the deeds from Knox to Deaver was properly a matter for the decision of the court; for, though the jury must ascertain as a fact where the boundaries of a grant are, it is the duty of the court to declare what the boundaries are that control the location; (Doe v. Paine, 4 Hawks, 64;) and, under the circumstances of this case, the court properly might have charged that the land conveyed by the first and third deeds was bounded on the north by the Lami or Cerré tract, and that therefore nothing passed by the deed to Dorwart under which the plaintiffs claim.
The objection, that a witness was allowed to give his opinion as to the location of the land described in the deeds, may be answered by repeating what was said by this court in Evans v. Greene, 21 Mo. 210, that a judgment will not be reversed because “ a witness has given his opinion upon a matter of law, when we see that the opinion given was sub*408stantially correct and could not have prejudiced the party complaining of it.” The other judges concurring, the judgment will be affirmed.