This is a proceeding under section 3979 of the Code for the correction of the assessment returned by the Tennessee Goal, Iron & Railroad Company of its lands situated in Shelby county. Under that section the Commissioners Court of the county not only had the power but it was its plain duty to increase the valuation set down in the assessment returned by the company, if it was found that such valuation was inadequate, “and fix it at the sum which the evidence showed to be the fair market or real value” of the land. This expressly conferred power was to be-exercised and this mandatorially imposed duty was to be performed *108by the commissioners wholly without regard to any suggestion made before them by the tax commissioner as to the real yalue of the land. They were to determine and fix that value on the evidence before them and without reference to the motion' of the tax commissioner wherebv that officer alleged that the real value was, a stated sum to which he prayed the valuation set down in the assessment be increased. If, on the evidence the commissioners found the true valuation. tO' be greater than the assessment showed but less than the sum suggested fr" the tax commissioners, the intermediate valuation should, of course, have been fixed and declared by them. So had they found the true value to be a sum beyond that, so suggested, their plain duty was to, fix and. declare that sum, the estimate of the tax commissioner to the contrary notwithstanding. The commissioners having found on the evidence that the valuation claimed by the tax commissioner was the true valuation of the property, the taxpayer’s appeal from that, finding to the circuit court opened up the whole inquiry anew and for original investigation and determination in that tribunal. On that appeal the power and duty of the circuit court were precisely the same as had been the power and duty of the commissioners’ court; to fix the valuation at the sum which the evidence adduced in that court showed to be the fair market or real value of the land, without regard to the suggestion made by the tax commissioner in the commissioners court and without regard to the conclusion reached by the commissioners court. In the circuit as in the commissioners court, the assessment returned, by the taxpayer was to be taken prima facie as correct; but this operated only to lay the burden of averment and proof of circumstances and. greater valuation upon the State, and in no degree to limit the court, the burden being discharged, in respect of fixing the true value. ITence, it is, that it was entirely competent for the State on appeal to insist that the true value was not only greater than that returned but also greater than that claimed by the tax commissioner and found by the commissioners court, and that it was not only competent for the circuit court but its clear *109duty to fix the fair market or real value of the property according alone to the evidence adduced before it. It was, therefore, no objection to the complaint filed by the State in the circuit court that it claimed a valuation in excess of thát found by the commissioners, nor is it any objection to the conclusion and judgment of the circuit court that thereby a valuation beyond that claimed and adjudged in the commissioners court was found and fixed. The taxpayer takes the risk of such increase of valuation when he appeals to a tribunal having the power and under a duty to find and declare such increased valuation if the evidence established it as the fair market or real value of his property.
Nor is there merit in the suggestion made for appellant that the proceeding was wanting in an assessment to support it. There was an assessment; that made and returned by the taxpayer. The case is wholly unlike those which arise in respect of property which has not been returned by the owner nor listed for taxation by the assessor, and of which the back tax commissioner is authorized and required to make assessment.
There was evidence to the effect that the lands under inquiry were* in the Cahaha Valley coal fields, and that they were of the same kind and quality as the lands in those fields. This evidence offered a predicate for the testimony which -was received as to tlie prices at which other lands there had been sold during or near to the time covered by the assessment. — 1 Greenleaf on Evidence, § 1, p. 91; Ladd v. Ladd, 121 Ala. 585, 586; Alabama Mineral Land Company v. Commissioners of Perry County, 95 Ala. 105.
But evidence of a mere offer to buy similar adjacent lands at a given price should not have been received to show the value of these lands. This Avas no- more than to show that the witness was at the time of the offer willing to give the stated sum for the property, and stands upon a footing analagous to that of an offer to prove that a person intended to bid a certain amount for the property the value of which Avas in issue, which was .held to be inadmissible in Ladd v. Ladd, supra. The offer is *110upon a lower plane as evidence of the would be purchaser’s estimate of value than actual payment by him for obvious reasons, and many considerations having no bearing upon the market value might have conduced to the owner’s rejection of it; and to receive such evidence in any case of. this sort may well lead to collateral inquiries and confusion of issues.
Courts do not know ivhat relation a given royalty in the lease of coal lands bears to the value of such lands. No evidence was adduced going to show that coal lands of a lea'se value of five cents per ton of mineral coal was of a certain market value in fee. The circuit court erred, therefore, in receiving the evidence of the witness Griffin that he had leased lands in the vicinity, and of like quality as those involved here for five cents per ton royalty; and his further testimony that as a part of this lease contract he was given the option to purchase the lands at twenty dollars per acre, was also irrelevant to the question at issue. A mere option to purchase, certainly one thus connected with a lease, is not competent in evidence upon the inquiry as to the market sale value' of similar lands in the same vicinity.
In receiving evidence of the offer to which we have referred, and of the lease, royalty and option testified to by Griffin, the circuit court erred. The fact that the hill of exceptions does not nurport to- set out all the evidence cannot open the way for an assumption on our part that there was other evidence which rendered this admissible. These errors appearing by what the bill of exceptions does show, they must operate to reverse the judgment in the absence of anything else in the record, to put a different phase on the'rulings inherently or to show that they did not prejudice the appellant.
Reversed and remanded-