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Notes in italics from Hampshire and the Isle of Wight by Nikolaus Pevsner and David Lloyd (1967)
Yale University Press, New Haven and London.

The thrill of the church - more for unexpectedness perhaps than for strictly architectural quality - is George Dance's centre octagon inserted into what had been a normal medieval church.

Of that church the W tower remained standing. It is of flint and stone and has a higher stair-turret and four-light bell-openings with a transom. The arches of the lights are uncusped; so it will probably be temp. Henry VIII. ... Dance was ruthless. His octagon, which was built in 1808, is of brick, showing bluntly outside and without any finesses of mouldings for the windows, let alone stone dressings. The walls are bare below - windows are only on the clerestory level, and they are just arch-heads.

The interior is less rigid. Four shallow niches in the diagonals, two deeper ones instead of transepts. All surrounds are of fine continuous mouldings. Plaster star-vault.

The mediate between the tower and the octagon Dance introduced a bay of transition of which the sides are the beginning of the medieval arcade, but the E arch may be the re-used chancel arch and E responds. 

The present chancel is of 1880-1*, and at that time windows with flowing tracery were introduced, not only in the chancel E wall.
* Probably by Colson who (according to the Rev. Basil Clarke) did the reredos in 1883.

On the south wall of the chancel: A group of three Baring monuments by Flaxman. ... They were made between 1801 and 1813. ... The two side pieces are: Thy Kingdom Come, a mother and child carried heavenwards by a tangle of angels, and Deliver us from Evil, a figure battling devils and helped by angels. (The centre piece, less interesting, is not shown).