Opinion by

On the trial of an action to recover damages caused by the opening of a street the defendant called a witness who testified as an expert to the value of the land before and after the street was opened. On cross-examination this witness gave an estimate of the value of each piece of land after the street was opened, *225and stated that the estimate did not include the cost of street improvements. He was then asked: “ What would the street improvements cost?” This question was objected to by the counsel for the defendant, and the objection was sustained. This gave rise to the only exception taken during a trial of unusual length, and to the only matter now presented for consideration.

The cost of future municipal improvements cannot be shown to establish an independent item of claim for damages caused by the opening of a street; but it is the undoubted right of either party to ascertain by cross-examination whether the witnesses of the other in estimating the difference in market value before and after the opening have taken into consideration the probable expense to the owner of such improvements, and the effect which they would have upon the value of the land : Harris v. R. R. Co., 141 Pa. 242; Dawson v. Pittsburg, 159 Pa. 317; Reyenthaler v. Philadelphia, 160 Pa. 195. It would have been competent to have tested the correctness of the witness’s estimate by questions directed to show what elements of advantage or disadvantage to the properly he had considered in forming his opinion, but the question asked disclosed no such purpose. When it was objected to, no offer was made to sustain it, and there was no explanation of its purpose. Presumably it was an attempt to show as an independent matter the cost of future improvements, and there was no error in sustaining the objection to it.

The judgment is affirmed.