delivered the opinion of the Court. The appeal is taken in this case in an action of ejectment, instituted in Charles county court, for the recovery of two tracts of land, called Rotterdam and William and James. The defendant took defence on warrant, and plots and explanations were returned in the cause. In the progress of the trial, five bills of exceptions were signed by the court, at the instance of the appellant, which it has now become our duty to revise and decide upon.

It is the modern practice, in location causes, to offer in evidence all the plots and explanations returned under the warrant of resurvey. This we commend as an excellent course, well calculated to lay the whole subject litigated, explicitly before the court and jury. It has not been pursued in the case under consideration; but the plots and explanations are, nevertheless, adverted to in the proceedings, and are sufficiently before us, to claim our attention in disposing of the points we have to act upon.

We concur withthecourt below, in their opinions delivered in the first and last (th e fifth) bills of exceptions; but we must beg leave to dissent from those expressed by them, in the remaining bills of exceptions. In the first bill of exceptions the court were right in rejecting the letter, plot and explanations, of the deceased surveyor, Theophilus Hanson, and in not permitting *157them to be laid before the jury. They contain no legally correct information, and are made up mostly of statements and opinions. Unlike the case of Snavely v M'Pherson & Brien, 5 Harr. & Johns. 150, they do not give his declarations of former runnings, which he performed as a surveyor, or to which he was in any way a witness. He speaks, it is true, of a survey made between the years 1760 and 1776, when he acted as an assistant to his father, in locating a vacancy taken up by Whcton Wallace, yet he does not designate it on his plot with sufficient precision to be understood, or to ascertain the place where the line of William and James sometimes called its first line, formerly run. He well remembers that it run a considerable distance into the possessions and cultivations of the tenants on the William and James; but the exact distance it run is undetermined, and the possessions and cultivations are not delineated on his plot. The old Peach Orchard he has mentioned, is not located by the plaintiff on the plots in this cause, and we cannot readily perceive how it would be possible to give it an exact designation, on any particular part of them, from the very uncertain information derived from Theophilus Hanson.

It is to be collected from the depositions offered in evidence in the fifth bill of exceptions, that they were taken under a commission issued from the high court of chancery in the year 1713. But the record of the commission is not produced, neither does it appear by what authority, or under what law, it was issued; nor in what manner, or on what notice it was executed. If authorised, it seems to have been altogether an incomplete and imperfect proceeding, and the court could not have erred, we think, in refusing it admission to the jury.

In the second and third bills of exceptions, the court refused to the plaintiff the benefit of Thomas Burgess’s testimony, on the score of incompetency, on account of his supposed interest in the event of the suit. In this we clearly think their honours were wrong. " The objection to testify was made by the witness himself, but if it had come from a different quarter, it could not have been available. If Thomas Burgess had an interest, it is not located on the plots in the cause, and his own private plot made to demonstrate-it,- could not be received *158for that purpose. He was moreover called to swear against his interest, and it is not for a witness to excuse himself from giving evidence on this ground. Since the case of Taney v Kemp, decided in this court in the year 1818, 4 Harr. & Johns. 348, it may be laid down as a rule of evidence, that no person shall be exempted from giving testimony on the ground that his answer may affect his interest. What the particular situation of Thomas Burgess is, in respect to the lines of Rotterdam, or William and James, does not fully appear. But whether the-establishment of the boundary at B, deprives him of a part of his land, within the lines of his tract called Bye Fields Close, or subjects him to the plaintiff’s action, for a trespass on Rotterdam, or William and James, he is equally within the operation of the rule, and in neither case is entitled to exemption from giving evidence in this cause.

There is another difficulty arising out of the consideration of the second and third bills of exceptions, which we deem it proper to notice. Thomas Burgess declined to give evidence of the boundary at B, although, in the execution of the warrant of resurvey, he was at the place where it stands, and was called upon by the plaintiff to testify in relation to it. Ought he to have been rejected as a witness on the trial lor this cause? The usual course is to examine a witness on the survey, and to take his deposition de bene esse; and it is not the least among many advantages attending this practice, that the testimony of the same witness in court, is applied more readily to designate points on the plots, and is, therefore, more perfectly understood by the court and jury. This advantage is attained in this case. By Thomas Burgess being on the ground, atthe time of the survey, at the boundary B, where he was called upon to give evidence, no mistake can arise as to the place at which he was required to prove the boundary, and his testimony on the trial can be as well understood, as if it was a repetition of -what he had previously sworn in the country. Nor can we perceive that the.offer to swear him, could produce any surprize on the opposite party, as the intention to make him a witness to a particular and designated boundary, was explicitly avowed on the execution of the warrant. For these reasons we are of -opinion, that his testimony on the trial ought not to have been *159rejected on the ground that he was not a sworn witness on the resurvey.

The court below certainly erred in admitting to the jury, the evidence mentioned in the fourth bill of exceptions. Giles G. Craycroft was not on the survey, and did not show to the surveyor the division line, designated by the letters i. k. on the plots, and his testimony in reference to it ought not to have, been laid before the jury.

JUDGMENT REVERSED, AND PROCEDENDO AWARDED,