London.

Dear Charley:—

One evening this week we spent very pleasantly at the Royal Polytechnic Institution for the advancement of the arts and sciences in connection with agriculture and manufactures. There is a large theatre, where all sorts of lectures are delivered, at various hours, upon philosophical and other subjects. Lecturers occupy the theatre in succession, and take up about half an hour. These are generally men of respectable abilities. The building is full of curiosities. We saw the model of the human ear, about one hundred and forty times larger than the natural organ. We saw a diving bell in the great hall, which is frequently put into action, and visitors are allowed to descend. That evening several made the experiment. The interior of the bell is lighted by thick plate glass. A very large number of models are to be seen, and there is much to interest the spectator. We heard a fine lecture respecting the experiment of Foucault, by which the diurnal rotation of the earth is said to be rendered visible to the eye. Foucault is a young Parisian, who, whilst engaged in some investigations with a pendulum in his mother's cellar, made this discovery, as he claims it to be. We saw the experiment repeated here on the same scale as it has recently been shown at the Pantheon at Paris. A brass sphere, weighing about five pounds, was suspended from the lofty ceiling by a piece of music wire, and made to vibrate in one plane over a table graduated into degrees. After a few vibrations, the direction of the pendulum appeared to be changed, as though the table had moved round on its owns axis.

We passed an hour at the Egyptian Hall to see the opening of the American Panorama of the Overland Route to California. It bids fair to make a hit in London. Last Sunday, "great exhibition" sermons were abundant in London. Exeter Hal, the largest place in London, holding about five thousand persons, is to be used for three months for the performance of divine service, to accommodate the strangers who crowd the city. We all went, Sunday evening, and heard the Rev. Thomas Binney, who has quite a reputation. The hall was as full as it could be, but we did not think the discourse as good as it might be. It was rather declamatory.

You no doubt remember how much our curiosity was excited by hearing that Mr. Wyld was about to place a model of the globe, of gigantic dimensions, in the great exhibition. Well, he was unable to obtain the space required, and so he has erected a spacious building in Leicester Square. This building is circular, with projecting entrances at the four cardinal points of the compass. From the centre rises a graceful dome. Here is placed the model of the earth, fifty-six feet in diameter. The scale is about ten miles to an inch. The arrangement before used in the construction of globes is reversed in this case, and the continents, islands, and seas are seen on the inner surface. This seems like turning the world, not upside down, but inside out. The mountains and land are elevated to a scale. The spectators travel round the globe on winding staircases, at the distance of a few feet from the surface. I went the other morning to the model, but was far less interested than I expected. The rest of the party were not present, and are willing to take my report. I heard that Mr. Wyld has spent twelve thousand pounds upon his undertaking.

We selected a fine afternoon to visit the ZoÖlogical Gardens in the Regent's Park, and, of course, had a treat. I did not think much of the gardens as far as the horticulture was concerned; but the collection of animals was far beyond any thing I had before witnessed. There are more than sixteen hundred specimens. The animals are finely housed, and their habits consulted in the arrangements of their homes. We had the pleasure to see the young elephant, only six months old, which had just been received. It was about the size of a donkey. A hippopotamus had recently been added to the collection, and we were sadly vexed not to see it. It was shut up at six o'clock, just as we reached its house. George had his luck, and obtained a glimpse of the retiring quadruped. We have been greatly amused with the sight of hundreds of boys about town, dressed in blue gowns, or long coats with belts, short knee breeches, yellow stockings, and shoes with tackles, but wear no caps or hats. In all weathers they are bareheaded. I find that they are the boys belonging to Christ's Hospital, a school founded by Edward VI., in 1553, and generally known in London as the Blue Coat School. The scholars generally range from one thousand to twelve hundred. The education, is said to be of the best character, and many of the boys belong to families of high respectability, and it is quite a matter of desire to obtain scholarship here. They look very funny in their old-fashioned rig. Each boy wears bands like a clergyman. The school is in Newgate Street, and is a fine modern edifice in the Tudor style. The front is flanked by towers, and has eight noble windows, which are separated by buttresses. Over one of the galleries of the hall is a fine picture, by Holbein, of Edward VI. granting the charter to the Hospital, as it was then called. Some of the best scholars of England were educated here; and we remembered particularly Coleridge and our special favorite, Charles Lamb.

To-morrow we are to have a treat of the highest kind. We are to spend the day at Windsor. I feel pretty well acquainted with its history and associations, but I shall spend the evening with George in brushing up my information. There is nothing more unpleasant than to find yourself in the presence of things and places of which you painfully feel an entire ignorance. If ever we meet again, how much we shall have to chat over on our favorite topics!

Yours always,

james.