The drawing corresponds more or less to drawing 2, though the elevation with twin doors is omited to allow space for the reduced plans. Inevitably, there is some updating of the design: the tall windows now go down right to the floor which is not seen in any of the other drawings. The wall colours are more sombre, blue-grey and grey-green instead of a light green (or pink on drawing 2) and the columns are washed in brown and not left white.

The drawing is one of many bound into a copy of Soane's unpublished 'Memoirs of the professional life of an architect between the years 1768 and 1835 written by himself' that was privately printed in 1835. (see Catalogue of Soane's library)

Soane's drawing for the print maker was to illustrate an episode in the relationship between the Bishop of Derry and himself. 'I shall now notice some architectural designs made for the Lord Bishop of Derry in 1778 and 1779, among which was one for a summer dining-room, to be added to his Lordship's mansion, the Downhill, in Ireland. The novelty and singularity of this composition, which was in imitation of one the rooms at Claremont in Surrey, executed from a design made by me during the time I was employed by the late Mr. Henry Holland, created much discussion among the young artists in Rome; and it was whispered that my design was a copy of another made by Mr. Henderson for the Bishop of Derry before my arrival. As I had never seen nor even heard of these drawings, I requested to have the two designs inspected. The proposition was acceded to: I named Mr. Brettingham, and Mr. Henderson named Mr. Hardwick, a pupil of Sir W. Chambers, as umpires. The referees met, and after examining the two plans, Mr. Hardwick observed, "He could not say they were exactly alike; yet he "considered them so much in the same character, that the one might gave given birth to the other." Mr. Brettingham replied, "I see no similarity in the plans. Mr. Soane's is a parallelogram, and quite original; Mr. Henderson's is an oval, without pretensions to any originality; in fact, Mr. Henderson's entire plan, with its columns and recesses, is to be found in many of the works of Palladio, Vignola, and others." Here the conference ended.