The Duke of Northumberland had the kindness to show me his fine palace to-day in detail. I here found what I had long vainly desired to see,--a house in which not only the general effect is that of the highest splendour and elegance, but every thing, the greatest as well as the smallest, is executed with equal exactness and perfection,--'ou rien ne cloche.' Such an Ideal is in this instance completely realized. You do not find the smallest trifle neglected, not a line awry, not a speck of dirt, nothing faded, nothing out of fashion or keeping, nothing worn out, nothing sham, not an article of furniture, not a window, or a door, which is not, in its way, a model of workmanship. This extraordinary perfection has indeed cost several hundred thousand pounds, and doubtless no little trouble; but it is perhaps unique in its kind. The richest embellishment from works of art and curiosities is also not wanting. The arrangement of the latter on terrace-formed shelves covered with violet velvet, behind which are looking-glasses in one piece, is very tasteful. One of the most striking things is the marble staircase, with a railing of gilded bronze. The hand-rail of polished mahogany at the top is a curious piece of workmanship: by some contrivance, which remains a secret, the wood is so put together that it is impossible to discover a single joint from top to bottom. The whole seems to be made of one piece, or is so really. Another remarkable thing is the false 'porte cochère' in the outer wall, which is only opened on occasion of a great press of carriages; and when closed, cannot be detected in the façade. It is of iron, and so completely masked by a coating of composition stone and a false window, that it cannot be distinguished from the rest of the house.--Of the pictures another time. At the Duke of Clarence's, in the evening, I made the acquaintance of a very interesting man,--Sir Gore Ouseley, late ambassador to Persia, who was accompanied by Mr. Morier, the author of Hadji Baba, as his secretary of legation. I must tell you two or three characteristic anecdotes of that country, which I heard from him.