Frogmore Lodge, the Princess Augusta. - We have so often before mentioned this quiet retreat, that we shall have very little to say of it at present. It is in good order; and there is a fine display of the flowers of the season. We particularly noticed a collection of picotees and carnations, raised from German seeds, which we brought over for Mr. Ingram, from our correspondents at Stutgard, M. Hertz and M. Bosch, in 1829. Among these are a number of new and beautiful varieties. We observed also some new calceolarias, hollyhocks, and georginas, raised by Mr. Ingram; and fine collections of that fashionable flower, heartsease. We measured the trunks of two fine evergreen oaks in the pleasure-ground, and found one, at the height of 2.5 ft. from the ground, about 10 ft., and the other, at the same height, about 12ft. in circumference. There is a neat Swiss seat now erecting near the lake, which has been lately cleaned, and two large pikes, which had devoured almost all the other fish, one weighing 19 lbs. and the other 22 lbs., were taken.