After making a tour through the principal parts of the town, and getting my passport signed by the police and English ambassador, I made a second visit to Mr. Otto, and also then called on Dr. Kloytch, to whom I had a letter of introduction from Sir W. Hooker. Dr. Kloytch has the charge of the Royal Herbarium, which is situated opposite and nearly adjoining the Botanic Gardens, containing several apartments for dried specimens of all the plants that flower in the Royal Botanic Gardens, which are gathered and preserved as they appear in flower. Attached to the Royal Herbarium house is a piece of pleasure ground, one side of which is enclosed by a good brick wall that has projecting piers, betwixt which grape vines are trained, and confined to the spaces of about twelve feet between the projecting piers; each sort is thus prevented from intermixing with another; a wooden pailing enclosing another part of this garden is likewise adapted to the same purpose. Dr. Kloytch was once a pupil of Sir W. Hooker's at Glasgow, and is considered an eminent botanist, he has certainly formed a very natural arrangement of the different species in the genus Ericæ, arranged according to the form and structure of the flower. He shewed me several native specimens of this genus that I have not yet seen in England, but seeds of which I hope to receive from him before long. I was much gratified by the excellent method he described to me, in preserving the specimens of Fungi, which appears to be the most effectual mode of drying these plants that I have yet seen. After looking over various specimens in the Herbarium, Dr. Kloytch accompanied me to the Botanic Gardens, where I again saw Mr. Otto, and was enabled to see more minutely the extent of this noble collection of plants. It is proper to observe that the space of ground allotted for this garden, is not sufficiently large for such an extensive collection of plants. Many of the oaks and several other fine trees are too much crowded, and not seen to advantage. After examining all that I wished to see here, Mr. Otto, Dr. Kloytch, and Mr. Brackenridge, accompanied me into Berlin, where we passed through another fine part of the "Thiergarten," and being joined by Mr. Cuming, the celebrated Zoologist, we spent a very pleasing evening in the discussion of botanical pursuits, and the cultivation and beauty of the Cacteæ in the Berlin Gardens.

August 29th. Left Berlin at seven o'clock in the morning for Potsdam, where I arrived at eleven o'clock in the forenoon, a distance of eighteen English miles. Every stranger must be forcibly struck with the scenery as he approaches Potsdam, particularly in passing Prince Charles's villa and grounds, with the view of the handsome bridge lately erected across the river Havel, at this side of the town expanding itself to a very capacious sheet of water. On my arrival at Potsdam I proceeded to the Royal Gardens at Sans-souci, which are situated about one English mile distant. Having a letter of introduction from M. Otto to M. Linne, the principal director, I was disappointed in not finding him at home. Free access was afforded to the various departments, and I then made the best use of my time in examining the different gardens attached to this residence, which required considerable diligence to get through a portion of the departments. I first inspected the kitchen garden, which is very extensive, and contains several ranges of low houses, and pits, for the forcing of cherries, plums, and apricots, with a good collection of standard fruit trees, as well as the walls being well stocked. The length and breadth of the principal range of houses in this garden, is 255 feet long, and about 9 feet in width; the upright sashes are eight feet high, placed in a slanting position; the roof-lights were about six feet long, but these lights were at this time all removed from the house, the trees being planted as standards in the interior border; the sashes are removed as soon as the fruit is gathered, in order to expose the trees to the full effect of the atmosphere. In another garden at a short distance from this vegetable one, there are numerous other ranges of hothouses for the forcing of fruits, which are in great request for the royal table. The structures here used for this purpose are about six feet high in front, and about ten feet in width; the length of the roof sashes were from nine to ten feet. In these houses the flues are placed at the back, running parallel to the backwall. Some of the houses are heated by hot-water pipes, rather of a novel construction, and I much fear not calculated to give any great command of heat; they consist of two round copper pipes, about two inches only in diameter, which run parallel along the front of the house about two feet apart from each other. The peach trees are planted inside the house, within one foot of the front wall, and are trained perpendicular to the trellis, to the height of six feet, being as high as the upright glass. A rider is then carried in general, close under the roof lights, trained to a lath trellis which is nailed to the underside of the rafter.

As soon as the frosty nights are over, the houses are generally stripped of the sashes, and the trees and fruit left fully exposed to the sun and weather, while the fruit is maturing; but such fruits as are wanted at an early period, are of course not thus exposed. I here observed various trees of plum, cherry, and apricot, thus treated, a more congenial mode of treatment, than by having recourse to pots or tubs, as is in general practised in this country, especially where there can be houses spared for this purpose, as the trees will get established in the ground, and be enabled to produce a more abundant crop and larger fruit than if their roots were confined to a small space for nourishment. I also saw here a great quantity of very fine melons, all trained over moss, and at this season these also were exposed to the weather. The appearance of the fine terraces in front of Sans-souci Palace, gave me more gratification than anything of the kind that I had previously seen. This palace, originally erected by Frederic the Great, is now a favourite summer residence of the Crown Prince. It is situated so as to command a most beautiful view of the surrounding country, with six tier of terraces in front of it, each terrace falling about twelve feet under another towards the south from the palace. Along the top are flower borders and broad gravel walks, with a row of very fine orange trees placed along the edge of the gravel walk on each of the terraces, which give them a magnificent appearance. Against these walls are trained principally grape vines, provided with a frame in front for covering them with glass; peaches and apricots are likewise here grown.

In the centre of each terrace is a noble flight of steps thirty-six feet wide at the bottom, but at the top the width is only fifteen feet; containing in each from twenty-five to twenty-seven steps. The view of these from the avenue or road by M. Lennie's house, is really grand: the different flights of steps from this point of view appear to form one connected tier leading to the palace, which, with its magnificent orange trees and groups of sculpture, strike the eye of every stranger with admiration. I here congratulated myself on being alone, and left to examine and take the dimensions of the various objects, without being hurried. At a short distance from the lower terrace is an oval basin of water, surrounded by a grass lawn and a gravel walk, or rather carriage drive; and on the exterior side of the circular sweep of the gravel, are placed twelve large statues. This basin was originally intended for a fountain; the reservoir for supplying it was formed by Frederic the Great on an eminence on the north side of Sans-Souci palace, where it must be several hundred feet above the level of the basin of water where the fountain was intended to be placed. The effect from the palace windows and from several other points of view, if it had been completed, would have been very magnificent when the water was playing. At a short distance from the palace is another large building, which was occupied by a part of the establishment; in front is a large piece of pleasure ground, in which are placed also a number of very fine orange trees; one of them, pointed out to me, is named after Frederic the Great, his majesty being a great admirer of these trees, insomuch, that during the war he took possession of all the best that came in his way, and sent them to his royal gardens at Potsdam. The head of this tree, named Frederic the Great, was equal to one of our ordinary sized Portugal laurels, its branches extend over seventeen yards of ground in diameter. I should imagine there must be fully 400 trees grown in this establishment, all of large dimensions. The soil in which they are grown consists of a black sandy loam, well incorporated with cow-dung and rotten leaf mould, with a mixture of bone dust, in some cases horn shavings. The houses for the protection of the orange trees in the winter season, are simply a long range or ranges of red tiled roofed buildings, with merely upright lights in the front or south side, which are provided with wooden shutters that are closed during frosty weather. The flues run along in the floor of the house, and are not calculated to give out much heat, but the roof and back wall being opaque, and the front furnished with shutters, little heat is required for preserving the trees from the frost. They are generally turned out of doors in the month of May, and not taken in again until October. Arranged along with the orange trees I observed a very fine specimen of the Nerium Oleander, covered with blossom, also several fine plants of the pomegranate, covered with flowers. The figs were also in prolific state against a wall and growing in light sandy loam. At the opposite end of the palace is situated the picture gallery, which opens into another garden department, with hornbeam hedges, and numerous box edging scrolls; but this piece of ground is evidently not much attended to: the walks, flowers, borders, are not in good order. The collection of paintings, however, in the gallery will infinitely repay the visitor for the disappointment he may experience in the badly kept garden. This gallery is two hundred and fifty-two feet long, and thirty-six feet wide; the dome and cove ceiling are richly gilt, the floor and walls inlaid with marble. The paintings are very numerous, and in beautiful preservation. Those taken from this gallery by Buonaparte and again replaced in the spot they originally occupied, are particularly pointed out to the visitor. I observed on each side of the door, as we entered this gallery, two very fine marble statues, one of Diana, the other of Louis XVI. A straight avenue or drive leading from the Potsdam road, in a direct line by the front of the terraces at Sans-souci, to the new palace, is of considerable length. At the extremity of this avenue is the magnificent palace built by Frederic, after the completion of the wars in which he was engaged. It is said to have been erected with the English subsidy; however this may be, it is undoubtedly a very magnificent building.

The grounds leading from this and Sans-souci palace are all laid out as pleasure-ground, with numerous walks and roads, leading in various directions, which are very well kept; but the grass lawn here is rather rough, and not much attended to. The quantity of sculpture placed throughout these grounds is truly astonishing; at almost every intersection of the walks, various statues or busts are placed, and likewise in different recesses that are formed out of the road and walk edges.

Along the front of the new palace, facing towards Potsdam, is arranged a row of very fine orange trees, with several pieces of sculpture.

The garden ground extends considerably to the north of the palace, where it is much varied, and commands an extensive view of the adjoining scenery and country. The Belvidere and terraces here are also prominent objects. I was much pleased with a piece of trellissing that surrounded the oval spot of ground at the south side of the palace. This trellis projects about twenty-one feet on one side, and forms an oblong square about forty-two feet long. The side next the oval consists of eight round columns, formed by thin flat iron bars, opposite to which are openings to correspond, that look into a running stream of water, that separates the park or pleasure ground from a piece of kitchen-garden ground on the opposite side. The peculiarity of this trellissing is in its handsome projecting cornice, with columns at nine feet apart, formed by the flat iron bars. Arched recesses are likewise made between these columns, about five feet wide, and nine feet in height. The entire height of this trellis with the cornice is twelve feet, and was evidently originally gilt, but it is now in a corroded and decaying state; not a vestige of paint is even to be seen upon it.

At a very short distance from this splendid palace is a piece of vegetable ground enclosed with formal clipt hornbeam hedges, which ought to be removed, as it disfigures that part of the grounds, and is much too close to the palace. The walks and lawn adjoining were in pretty good order, especially the former.

Leading from the palace to a royal chateau that has been lately erected, is a very fine carriage drive, winding through a flat piece of ground, which is laid out principally after the English fashion. This residence is also inhabited by one of the royal princes. I was much pleased with the quantity of grapes growing on a double terrace, or rather covered walk, which was completely crowded with vines and its fruits; the lower walk ran alongside of a wall, and the trellis and arches projected about twelve feet from it, and were twelve feet in height. Over the top of this wall is another trellissed walk, which is also completely covered with grapes; it leads up to the palace windows, and is about two hundred feet in length. Adjoining it, and in front of the windows, is a small flower-garden, elevated above the ground level I should imagine about twelve feet: we ascend to it by a flight of steps at the furthest end; the side next the palace is nearly on the same level as the window sills. There are several fountains in it, and a few clumps of the Petunia violacea, but nothing else of interest.

Connected with this terrace garden, but on the ground level, is a piece of ground laid out in various beds, principally furnished with dahlias. Here is a handsome marble fountain or column, and a well formed sheet of water.

About three hundred yards from this spot is Charlottenhoff, a handsome erection, which is used occasionally as a tea or coffee room. This building is surrounded by numerous walks, and columns with vines trained against them. Ascending a flight of steps, that leads to a point of view looking down upon a fountain, playing with great force. This spot is tastefully laid out, and in very neat order. Several other ornamental erections are placed in these grounds, but to attempt to describe them all would require an actual residence for some weeks. The royal palace of Potsdam is a magnificent building, in the form of a quadrangle. The interior apartments contain numerous objects of interest, which as being highly estimated by Frederic the Great, are particularly pointed out to the stranger. The arm chair which he was in the habit of using, is still in a good state of preservation; I was much pleased with the magnificence of the rooms; the paintings and furniture are very splendid, and in good preservation. The ground attached to this palace consists of a flat surface, extending towards the south, as far as the river Havel, and is laid out in clumps of trees, various walks; the space next the palace is a larger piece of gravel, which is daily used for the exercise of the military. Adjoining it are numerous avenues of horse chesnuts, and busts of ornamental sculpture placed along the first row of trees, as well as some in various other positions. Opposite the south, or principal front of the palace, is an oblong piece of water, in the middle of which is placed a noble group of Neptune and his sea horses, which has a very grand effect, but the water is kept rather low and filthy, which might be easily remedied, as the river Havel passes within a few yards of it. By the edge of the river, in a marshy spot of ground, I observed a large quantity of the Hydrocharis morsus-ranæ (Frogbite,) and Stratiotes aloides, (water soldier,) growing in great abundance.

I should however have observed that the fine marble group of Neptune was much injured by the French army, during the time they occupied Potsdam. In short it is really grievous to see the depredations that were committed by that army on the sculpture about Potsdam and Sans-souci, whilst they resided there. The soldiers for amusement were in the habit of firing musket balls at the different groups and statues.

August 30th. Left Potsdam at eight o'clock in the morning, for the Pfauen Insel, or Peacock Island, where I had appointed to meet Mr. Cuming at nine o'clock. We had to cross a branch of the river Havel to get to the island, which contains a collection of plants and animals somewhat resembling the Zoological Gardens in Regent's Park. I was here more fortunate in finding M. Fintelman at home, than I was at Sans-souci, and having a letter of introduction to him from his uncle, who superintends the royal gardens at Charlottenburg, I found him remarkably attentive, and an intelligent young man. I was here surprised to find the Robinia pseudacacia had attained seven feet in circumference, at four feet from the ground, the branches of which extend over thirty two yards of ground in diameter. I also observed some fine specimens of the oak, which were little inferior to our largest English oaks. The conservatory is an oblong building, about one hundred and twenty feet by forty, and forty two feet high, and consists of several tiers of front sashes, with a span roof, the north side being a dead wall with a gallery for resting in behind it, which commands a full view of the plants underneath.