"Mac" and "Mc" names are not always easy. Mostly, the "mac" part is unstressed, but not always. For instance, the word "mackintosh" (which also means a raincoat, presumably after its designer) is stressed on the first syllable, whereas Macmillan, the name of a former prime-minister of Britain and also a contemporary poet is stressed on the "-mill" part. Macaulay is pronounced /mö-caw-li/, the "-lay" part is pronounced "-li". Do not be distracted by Oil of Ulay, the face cream or hand cream, or whatever it is.