We hold that the doctrines of res judicata and estoppel by judgment are applicable to awards of the State Board of Workmen's Compensation on all questions of fact in matters in which it has jurisdiction. See Code § 114-710; Jones v. American Mutual Liability Ins. Co., 48 Ga. App. 351, 353 ( 172 S.E. 600) (1933); Noles v. National Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185) (1969). The Georgia constitutional right to trial by jury is not applicable to the proceedings of the State Board of Workmen's Compensation. Metropolitan Casualty Ins. Co. of N. Y. v. Huhn, 165 Ga. 667, 671 ( 142 S.E. 121) (1927).

In a subsequent appearance of the case before the Court of Appeals, it was held that the claimant had a right to withdraw the stipulation from the record. Noles v. National Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185) (certiorari denied). Under these rulings by the Court of Appeals, it is the law of the case that the stipulation had no binding effect, and that it could be withdrawn from the record.

Accordingly, this action is governed procedurally and is barred by the limitation provision of the 1978 statute, even though to do so requires the utilization of the date of a transaction which preceded the effective date of the statute. Compare Noles v. Nat. Engine Rebuilding Co., 119 Ga. App. 833 (1) ( 169 S.E.2d 185) (1969). Judgment affirmed.

Not only is this agreement approved by the board, it is based on a hearing and board adjudication denying compensation under the "new accident" theory. The award in claim No. 7419, not having been appealed, is res judicata to the effect that the 1972 incident did not constitute a new injury. Arnold v. Indemnity Ins. Co., 94 Ga. App. 493 ( 95 S.E.2d 29); Noles v. Nat. Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185). Under Code § 114-606 "the insurer or insurers shall in all things be bound by and subject to awards, judgments, or decrees rendered against such insured employer." And Code § 114-607 provides: "No policy or contract of insurance shall be issued unless it contains the agreement of the insurer or insurers that it or they will promptly pay to the person entitled to same all benefits conferred by this Title and all instalments of the compensation that may be awarded or agreed upon, and that the obligation shall not be affected by any default of the insured after the injury, or by any default in giving notice required by such policy, or otherwise.

In like manner for the reason that the res judicata aspect of an award of compensation is substantive and vested, we have held that the 1968 amendment to § 114-709 providing that a change in condition as relates to §§ 114-404 and 114-405 shall mean "solely an economic change," is a substantive change and could not be applied to awards which antedated the amendment. McMullen v. Liberty Mutual Ins. Co., 119 Ga. App. 410 ( 167 S.E.2d 360); Noles v. National Engine c. Co., 119 Ga. App. 833 ( 169 S.E.2d 185); Hartford Accident c. Co. v. Carroll, 121 Ga. App. 78 ( 172 S.E.2d 869); City of Atlanta v. Price, 121 Ga. App. 340 (2) ( 173 S.E.2d 750); Hopper v. Continental Ins. Co., 121 Ga. App. 850 ( 176 S.E.2d 109); Jenkins Enterprises v. Williams, 122 Ga. App. 840 ( 178 S.E.2d 926). The right afforded by the notice given prior to the date of the amendment changing the law is vested and a subsequent change in the law, if applied to these cases, would run afoul of the Constitution, Art. I, Sec. III, Par. II (Code Ann. § 2-302), and Code § 102-104.

3. The board did not err in refusing the employer's request to make a retroactive finding, and an award based thereon, that disability terminated as of February 9, 1968, the date of approval of the 1968 amendment to Code § 114-709 (Ga. L. 1968, pp. 3, 7), since it has been held that this amendment cannot be retroactively applied. McMullen v. Liberty Mut. Ins. Co., 119 Ga. App. 410 ( 167 S.E.2d 360); Noles v. National Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185); Security Ins. Group v. Gillespie, 125 Ga. App. 163, 164 ( 186 S.E.2d 575). 4. The evidence authorized the finding that claimant had not undergone a change of condition since the original injury, for which he was receiving, and was entitled to continue to receive, compensation.

authorize a finding of a change in condition, such finding was not demanded; accordingly, the finding of the board, approving the finding of the single director, must be affirmed, but under the ruling in Atlanta Coca-Cola Bottling Co. v. Gates, 225 Ga. 824, supra, we must hold that an award of further compensation was not authorized in view of the finding of no change in condition, and the board erred in so doing. 3. The judge of the superior court, on appeal of the award by the employer, instead of remanding the case to the Board of Workmen's Compensation for an award in accordance with its authorized findings of fact, entered an order making his own findings of fact that a change of condition for the worse of the employee had occurred, and based upon his own findings affirmed the award of compensation, but only that accruing after the filing of the employee's application, the agreement having been approved prior to the 1968 amendment (Ga. L. 1968, pp. 3, 7) to Code § 114-709 (see Noles v. Nat. Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185), and remanded the case to the board with direction that it amend its award by deleting the retroactive portion thereof, that is, compensation accruing prior to the application based upon change of condition. The finding of the Board of Workmen's Compensation is conclusive upon the superior court ( Dill v. Ocean Acc. c. Co., 95 Ga. App. 60 (1) ( 96 S.E.2d 638); Wiley v. Aetna Cas. c. Co., 98 Ga. App. 241 ( 105 S.E.2d 377)), and the judge of the superior court on appeal has no fact-finding powers.

See, e.g., Lumbermen's Mut. Cas. Co. v. Cook, 195 Ga. 397, 399 ( 24 S.E.2d 309); Arnold v. Indemnity Ins. Co., 94 Ga. App. 493 (4) ( 95 S.E.2d 29); Hartford Acc. c. Co. v. Webb, 109 Ga. App. 667 (1) ( 137 S.E.2d 362). It must necessarily follow that since the board found the change in condition to have occurred on June 26, 1968, more than four months after the effective date of the amendment to Code § 114-709, there is no merit in the contention that the amendment was given an impermissibly retroactive effect by making the change-in-condition award effective as of that date. McMullen v. Liberty Mut. Ins. Co., 119 Ga. App. 410 ( 167 S.E.2d 360) and Noles v. National Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185) do not require a different result under the circumstances here. Davis v. Caldwell, civil action No. 14973, decided August 24, 1971, by the United States District Court for the Northern District of Georgia, Atlanta Division, is not in point, as it was there held that Code Ann. § 114-709 and Rule 17 of the board are unconstitutional only insofar as they invite and permit unilateral termination of previously adjudicated benefits without a hearing as to the recipient's alleged change of condition. 2.

The contentions of the claimant in this respect that the award is unsupported by the evidence and contrary to law are without merit. See City of Augusta v. Rosier, 119 Ga. App. 192 ( 166 S.E.2d 378). There is no issue in the present case of whether the award could include any period preceding the request for hearing, but in this respect see Noles v. National Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185). 2.

The superior court reversed the award on the ground that the 1968 amendment was not retroactive and remanded the case to the board. See McMullen v. Liberty Mut. Ins. Co., 119 Ga. App. 410 ( 167 S.E.2d 360) and Noles v. National Engine Rebuilding Co., 119 Ga. App. 833 ( 169 S.E.2d 185). The employer contends that only an economic change is required to carry the burden of proof under the law as it existed prior to the 1968 amendment. This contention was without merit at the time the superior court made its ruling.