Opinion by
For six months prior to his death, Samuel C. Heiney was aware that he had terminal cancer. During this period his physical condition deteriorated rapidly. Seventeen days prior to his death, Heiney executed a will devising Ms farm to Ms son L. Russell Heiney1 and directing the residue of his estate to be converted *576into cast and divided equally2 among Ms eigM cMldren.3
Six of decedent’s eight cMldren challenged the will. The only evidence presented to the register of wills by contestants was the testimony of a handwriting expert. The proponents of the will called the subscribing and attesting witnesses. The register found the signature genuine and concluded that contestants failed to establish either lack of testamentary capacity or undue influence.4
In the orphans’ court, the challengers requested that a jury be impanelled to decide the issue of testamentary capacity. The court refused this request and filed an opirnon in support of its decision. After talcing extensive testimony, the court affirmed the register’s decree and issued a second opinion. TMs appeal followed.5 We affirm.
Appellants have concentrated their attack upon the alleged lack of testamentary capacity. They contend that the orphans’ court erred in placing upon them the burden of proving the decedent’s lack of capacity. While admitting the general rule is that testamentary capacity is presumed, Brantlinger Will, 418 Pa. 236, 210 A.2d 246 (1965); Williams v. McCarroll, 374 Pa. 281, 97 *577A. 2d 14 (1953), appellants assert that this ease falls within an exception to the rule.
In Girsh Trust, 410 Pa. 455, 189 A.2d 852 (1963), this Court held that when a settlor for two years prior to the execution of an inter vivos trust had been under treatment for “paranoid schizophrenia,” and for four years thereafter was institutionalized, the presumption of competency had been overcome. The burden then shifted to those asserting the validity of the instrument to prove that it was executed during a lucid interval. Id. at 468-70, 189 A.2d at 858-59. See First National Bank v. Wirebach’s Executor, 106 Pa. 37, 46 (1884).
Here, however, the trial judge was justified in concluding that appellants failed to meet their initial burden of showing mental incapacity. Although appellants produced numerous witnesses who testified that in their opinions decedent’s mental faculties were declining, we cannot, on the instant record, conclude as a matter of law that the orphans’ court erred in refusing to shift to appellees the burden of proving testamentary capacity. Dettra Will, 415 Pa. 197, 201, 202 A.2d 827, 830 (1964). The evidence was in conflict. Credibility was the determining element. The scope of our review is limited to whether findings of fact are supported by sufficient evidence and whether there has been an error of law or abuse of discretion. Shewchuk Estate, 444 Pa. 249, 260, 282 A.2d 307, 313 (1971); Mintz Trust, 444 Pa. 189, 196, 282 A.2d 295, 299 (1971); Gramm Estate, 437 Pa. 381, 386, 263 A.2d 445, 447 (1970); Abrams Will, 419 Pa. 92, 101, 213 A.2d 638, 643 (1965). We conclude that sufficient evidence supports the orphans’ court’s finding that appellants had not established habitual unsoundness of mind or lack of testamentary capacity. The presumption of testamentary capacity thus survived.
It is also argued that the orphans’ court erred in not finding that the signature on the 1965 will is a *578forgery. Appellants presented a handwriting expert and several lay witnesses who testified that in their opinions the signature was not testator’s. The proponents of the will called a subscribing witness and an attesting witness. The orphans’ court, as finder of fact, accepted the testimony offered by the proponents. This was not error. Shewchuk Estate, supra; Mintz Trust, supra.
Forgery presents an issue of fact, resolution of which necessarily turns on the court’s assessment of the witnesses’ credibility. That the contestants produced expert testimony does not preclude the trier of fact from independently evaluating the evidence. Cline Will, 433 Pa. 543, 547-49, 252 A.2d 657, 660-61 (1969); Elias Will, 429 Pa. 314, 321, 239 A.2d 393, 396 (1968); Pochron Will, 367 Pa. 306, 80 A.2d 794 (1951).
Appellants raise one additional assignment of error. They urge that the orphans’ court erred in failing to submit questions of fact to a jury. The decision whether to impanel a jury is within the discretion of the orphans’ court.6 As we noted in Holtz Will, 422 Pa. 540, 544, 222 A.2d 885, 888 (1966) (emphasis in original), "there is now no statutorily-mandated right to a trial by jury in a will contest; the impanelling of a jury lies solely within the discretion of the chancellor. Moreover, since a jury verdict is now advisory only, the refusal of the chancellor to impanel a jury does not constitute an abuse of discretion . . . .”
*579The decree of the Court of Common Pleas, Orphans’ Court Division, of Lancaster County is affirmed. Each party to pay own costs.
Mr. Justice Eagen took no part in the consideration or decision of this case.