DAILY TELEGRAPH 7.12.94 Charles Spencer     AT 65; an age when most people are happy to bow out and collect their bus pass, Nigel Hawthorne, like Miss Jean Brodie, is still emphatically in his prime.     After his triumph in The Madness of George III (a role he has just repeated for an eagerly awaited film), he is now making his directorial debut in this unjustly neglected 18th-century comedy by David Garrick and George Colman.     After the harrowing emotional demands of George III one can readily understand why Hawthorne was drawn to The Clandestine Marriage. Unlike the Restoration comedies of a century earlier, it is a piece brimming with. good humour. And in the character of Lord Ogleby, a part Garrick wrote for himself but didn't actually play on its first night in 1766,. Hawthorne has found his finest comic role since Sir Humphrey in Yes, Minister.     Nevertheless, Hawthorne has overreached himself by both directing the show and starring in it. This is.one of. those frustrating evenings that, despite being full of good things, never quite adds up to a satisfying whole. The rhythm is jerky, and too many scenes find the company frantically overacting to rapidly diminishing returns. It all proved too much for the man sitting in front of me, who spent most of the evening slumped and snoring. Occasionally I felt like joining him in slumber.     You certainly want to avert your eyes from Timothy O'Brien's grey, impoverished sets, which recall the concrete brutalism of the 1960s rather than the elegance of the 1760s. And the overamplified harpsichord music that zanily punctuates every scene becomes increasingly irritating.     But the strengths of the play undoubtedly survive. Garrick and Colman recognised that greed, snobbery and the triumph of young love are the surefire ingredients of English comedy, and their beautifully constructed play brings a social-climbing merchant and his daughters' into violent collision with impoverished aristocracy.     Mr Sterling is hoping to gain a place among the nobs by marrying his elder daughter to Sir John Melvil, the trouble being that the said daughter is a hysterical termagant. Instead both Sir John and his amorous old uncle, Lord Ogleby, fall for the sweet-natured younger daughter, Fanny. There is a problem though. Fanny is already secretly married to her father's clerk.     The play is full of juicy roles, none juicier than Lord Ogleby, memorably described as a man whose "smiles and grins and leers and ogles fill every wrinkle in his old wizen face".     Hawthorne hilariously captures a man racked between romance and rheumatism, lust and lumbago. He looks like death warmed up, needs a veritable pharmacy of drugs to revive him each morning, and when he falls to his knees to declare his passion, he finds it almost impossible to get up again.     The actor's leery smiles of complacent delight when he believes his love is returned are a joy to behold, but he makes the character much more than a laughing stock. After the farcical capers of the final act, with the whole cast rushing about in their nightshirts, he belatedly realises what an ass he has made of himself and reveals a real generosity of spirit. It is a lovely moment and Hawthorne plays it to perfection.     Christopher Benjamin offers excellent value as the apparently amiable father who trades his daughters like second-hand cars, and there are energetic comic performances from Susan Engel as his terrifying old trout of a sister and from Deborah Findlay as his shrill, vindictive elder daughter.     With more subtlety and a smoother pace, this could be a great evening rather than an intermittently enjoyable one. And someone should shoot the harpsichordist.