AN EMPIRE OF THE EAST: Travels in Indonesia by Norman Lewis (Henry Holt: $25; 244 pp.) Norman Lewis, now 85, may once have been “one of the best writers . . . of our century,” as Graham Greene put it. You wouldn’t guess it from this volume, however, for “An Empire of the East” is an intermittently interesting but unexceptional travel book, one marred by an all-too-English tone of superiority. Not that Lewis isn’t sympathetic to the native Indonesians he meets, far from it; but he is prone to sweeping generalizations (“The Chinese have a crow-like avidity for the collection of foreign ceremonies for incorporation in the mixed bag of their own social pleasures”) and condescending judgments (a porter’s grin “reminded me of the ingratiating foolishness carved on the face of the Mickey Mouse (doll) lying on its back”). The two encounters just quoted occur while Lewis is driving around Sumatra, and that may be part of the problem, for he proves much better company off the road, as in East Timor and Irian Java (the Indonesian half of the island shared with Papua New Guinea). In East Timor, while staying in an orphanage run by Catholic nuns, Lewis learns the details of Indonesia’s well-hidden massacre of the Timorese beginning in 1975; it included the physical encirclement of guerrillas with a “fence of legs” composed of perhaps 80,000 dragooned men and boys. In Irian Java he spends time with both the hardscrabble Yali and more prosperous Dani tribes, and witnesses one of the ritual battles for which the tribes are famous; Lewis’s main guide, Catan, happily doffs his Western clothes to participate, but his wife confesses her displeasure at his dressing up in the traditional penis gourd and little else. One hopes she holds another, more damaging Dani tradition in equal disdain--the custom among women of cutting off their fingers and ears to express bereavement.