PINNING the British aristocracy to the dissecting board has long been a favorite sport of British journalists and writers and particularly for those whose aim is to argue a case for the abolition of hereditary titles in general and the House of Lords in particular.

Simon Winchester (no relation to the premier marquess of that name) appears at least to have started out with the same aim. Having talked to a fair sample of them he seems, somewhere along the line, to have lost his way. Like Cassius he certainly came not to praise them but in the final analysis stops short of burying them.

To be fair, for a journalist even as distinguished as Winchester to attempt to set out, in a matter of 300 pages, anything like a complete picture of the historic role of the British aristocracy is a daunting if indeed not an impossible task.

What goes on in the House of Lords? Who are these people? he demands to know, as if they were some kind of secret society engaged in presiding over the fate of the nation by the exercise of arcane and dark rituals. Indeed by page 25 Winchester has created a sinister aristocratic body worthy of the greatest writers of spy fiction. According to the author they are known as The Twenty-Five Invisibles.

"The Invisibles" he writes "prefer that their existence goes unnoticed: the membership is sworn to secrecy . . . publicly, such operations as it orders are carried out by a well known 'cover' organization amidst a political climate which its members variously describe as 'hostile' and 'marred by the worst kind of jealousies' . . . the prosecution of the battle against extinction is carried out with practiced, monastic silence."

Mario Puzo could not have done better. Alas, after this promising start Winchester fails to maintain the pace. Just when we are beginning to anticipate a scene when the Duke of Hogsnorton orders "in practiced, monastic silence" the taking out of a contract against rival Godfather the Earl of Nonsuch on the grounds that he is a blabbermouth, the scene fades and we are treated instead to a number of random sketches of a variety of dukes, marquesses, earls, viscounts and barons. Some are indecently rich, some just rich, some poor to a point of bankruptcy. Equally, some are amusingly eccentric, others respectable and boring to a point of distraction. Much like any group of people one might say. Like French deputies or American senators.

There is, however, one significant difference as Winchester is quick to point out. Although not all aristocrats are members of the House of Lords and certainly by no means all the members of the House of Lords aristocrats, it is dominated by a majority of members who sit by right of birth and not by right of democratic election. It is inevitable also that many of the aristocracy should be large landowners. Indeed, to own land used to be a prerequisite to enoblement. Thus Benjamin Disraeli had to borrow a considerable sum of money to buy an estate before he could be created Lord Beaconsfield. Today landownership is as emotive an issue with left wingers as hereditary peerages.

We have moved on a long way from the early days of the last century when John Wade in The Black Book was able to write "You may knock down Nathan Rothschild, although he was a very rich man, or a Worshipful Alderman, or even a right honourable Lord Mayor and the Justices will only charge you a few shillings for the liberty you have taken; but if you knock down a Peer, though he is ever so insolent, it is almost as bad as murder."

How far is the aristocrat a privileged person today? Surely Winchester cannot believe it when he states that "it is still taken as read by policemen and magistrates that it is unlawful to arrest a noble in a civil case for a period of forty days before and forty days after a meeting of Parliament." Like many other archaic pieces of legislation it may have remained on the statute book but like the traditional right of some earls to collect the "third penny" of taxes collected in their shires is held more in the breach than the observance.

Just the same it is right and proper that our noble lordships should be pulled up by the roots every now and again to see how they are getting on or what they are getting away with, and this book is a fair attempt to do just that. Winchester's book contains much that is of interest and many entertaining accounts and anecdotes. It is as good a bedside read for the fans of the aristocracy as for the abolitionists, although I doubt if it will change the opinion of either camp.

Like all books in this category written with the eye of the investigative journalist rather than the academic, it must inevitably contain a number of inaccuracies. Perhaps I might be excused for mildly taking Winchester to task for decreeing that my kinsman, the Marquess of Lorne, has never existed.

"There is by the way, no Marquess of Lorn (sic) nor has there ever been. The phrase is rhyming slang, of a rare kind, and means an erection," he writes mysteriously.

When I last saw the lad he was fit and well and striding over the wild acres owned by his father the Duke of Argyll.

I would also take issue with Winchester on the subject of baronetcies, hereditary knights entitled to the prefix of "Sir"--a rank which he declares to be so insignificant as to be almost held in contempt. On the contrary, there are many baronetcies reaching far back into history who have held the rank in such high regard that they have down the centuries resolutely refused all promotion and many in more recent times who have been offered a peerage and opted for a baronetcy as being a much more gentlemanly rank and not subject to Harold Macmillan's often quoted opinion of many peers as being unspeakably middle class. Incidentally, Macmillan himself, although he married a duke's daughter (Devonshire) has never accepted a title and has his origins firmly in good Highland farming stock.

Finally, when it comes to examining the wealth of hereditary peers, Winchester complains at the difficulty of computing it and declares them a devious lot, a criticism he does not appear to level at those mysteriously very rich who do not hold titles. The Duke of Westminster's wealth, for example, he declares with barely suppressed irritation to be computed at as much as 200 million. Adding it up on my fingers the other day I made it somewhere in the region of s1.5 billion worldwide but who is to argue about a penny or two?

Do not let this put you off reading Their Noble Lordships, particularly if you are one of those--and there are many --who is never bored by a lord.