When the General Assembly provided for a direct appeal to this court from a decision of the Board of Tax Appeals, it was certainly not its intention to make of this court a “super” board of tax appeals. The entire structure of the Department of Taxation and the Board of Tax Appeals, of *177necessity, requires some measure of finality in the Board of Tax Appeals.

In a long line of cases this court has laid down certain rules in an attempt to define the words, “used directly in manufacturing,” etc. Having done so it must repose in the administrative appeal board the power to apply those rules to the different factual situations as they arise. It is not the function of this court to substitute its judgment for that of the Board of Tax Appeals on such factual issues but only to determine from an examination of the record whether the decision reached by the board is unreasonable or unlawful.

From an examination of the entire record, this court is unable to find that the decision of the Board of Tax Appeals is unreasonable or unlawful. The decision is therefore affirmed.

Decision affirmed.