“Where a party has won and has got an order for costs the only reason that he does not get the money straightaway is because of the need for a detailed assessment. Nobody knows how much it should be. If the detailed assessment were carried out instantly he would get the order instantly. So the successful party is entitled to the money. In principle he ought to get it as soon as possible. It does not seem to me to be a good reason for keeping him out of some of his costs that you need time to work out the total amount. A payment of some lesser amount which he will almost certainly collect is a closer approximation to justice. So I hold that where a party is successful the court should on a rough and ready basis also normally order an amount to be paid on account, the amount being a lesser sum than the likely full amount.”