In Appeal of Carnegie, 357 Pa. 138, 53 A.2d 425 (1947), owners of the Carnegie Building appealed the City of Pittsburgh and Allegheny County's assessments for 1943-1945. At the trial de novo, the owners called three real estate experts who acknowledged that the Carnegie Building was leased. However, they did not base their estimates of value upon the realities. They sought rather to speculate regarding probable values by assuming the non-existence of the lease. The Court of Common Pleas of Allegheny County accepted this evidence and concluded that the owners had met their initial burden and proved the incorrectness of the official assessment record. Our Pennsylvania Supreme Court reversed. "Estimates of value ... which are speculative and conjectural and are not competent evidence of present actual value ... the valuation fixed by the court below was not based upon any competent evidence of record. The incorrectness of the Board's assessment has not been proven and it must, therefore, be reinstated." Carnegie, 357 Pa. at 141, 53 A.2d at 427. See also Chatfield v. Board of Revision of Taxes, 346 Pa. 159, 29 A.2d 685 (1943), where the testimony of the taxpayer's expert as to the property's future worth, or in an altered condition, was too speculative and fanciful to rise even to the standard of an opinion.