IT is easy to be jocose in dealing with our ancestors. But the biographer who is persistently jocose is more likely to cheapen himself than entertain his readers. "Count Rumford of Massachusetts" is the life of a brilliant and eccentric cosmopolitan figure in eighteenth century politics, science, and society. Yet Mr. Thompson seems far more bent in his book on playfully pointing out the quaint ways of our forebears in that remote age than on giving us a true picture of his subject. Perhaps no one else who has ever really read a book printed before 1800 has been amused by the old typographical character for the lower case "s". It is no funnier to one who is familiar with the period than the fact that men then were knee-breeches and not trousers. But Mr. Thompson quotes paragraph after paragraph to show how ludicrous this custom was, and it affords him an opportunity for a bad pun or two. There are other puns. The movement of the fleet during the evacuation of Boston by the British in 1776 reminded one witness, it is recorded, of a "moving forest." To which Mr. Thompson adds: "a Birnam Wood moving on towards Dunsinano, with reverse English."

It would be impossible, however, to spoil completely so good a story as that of the career of Benjamin Thompson, born in Woburn, Massachusetts, and Subsequently a Count of the Holy Roman Empire. He was as quarrelsome as he was captivating, as erratic as he was able. He was first a Loyalist spy in the Colonies, then Under-Secretary of State in England, Minister of War in the court of Bavaria, founder of the Royal Institution of Great Britain, and the generally accredited discover of the theory that heat is a form of motion. He laid out the Englische Garten in Munich; he was offered the first command of the United States Military Academy by President John Adams (his work as a spy never having been known until recently); he conducted investigations and wrote tracts on foodstuffs, cookery, and heating (he is called "the father of the modern fire-place"); in his old age he rode in the wintry streets of Paris clothed entirely in white because "more heated rays are thrown from dark bodies than from light," and he founded the Rumford chair in Physics in Harvard University.

Here is surely God's plenty for the biographer. Mr. Thompson has given us a good selection of the old stories about Count Rumford and has added some new ones which were worth telling. But his facetiousness and his habit of using Shaksperian tags on every possible occasion detract from the effect which the stories would have had if told in a less decorated manner. The common reader, for whom this book was obviously intended, need not be frightened by the semi-scholarly appearance of the book (bibliography, scattered footnotes, though no index). He may even find himself wishing for more honest facts and fewer tidhits illustrative of that so quaint life of the times.