Hoban’s inspiration

I got a substantive question from visitor Andrew on James Hoban’s sources which I have been unable to answer, but I know some regular readers have more insight into the subject:

I am curious about the possibility of James Hoban having used an architectural reference book when designing the White House front elevation.

A few months ago, when I was browsing in my local university library, I stumbled on the book The United States Capitol: Designing and Decorating a National Icon, edited by Donald R. Kennon (published by Ohio University Press, in Athens, OH, in 2000). On page 32 of this book is reproduced an elevation drawing of Leinster House (Hoban’s inspiration for the White House). The engraving in question was originally taken from the 1780 architectural reference book Views of the most remarkable public Buildings, Monuments and other Edifices in the City of Dublin, written by Robert Pool and John Cash.

This engraving is most notable because in one regard it seems to be an intermediate step between the actual Leinster House as built and Hoban’s final plan for the two-story White House. Specifically, the elevation is much as Leinster House actually looked in the 1780’s (judging by a 1792 painting reproduced in William Seale’s The White House: The History of an American Idea) except for the second-story window pediments, which are inaccurate.

The actual Leinster House has (and has always had, going by the painting in Seale’s book) window pediments that are arranged (in terms of rounded vs. pointed pediments) much differently than those on the White House first-story windows. However, the engraving of Leinster House published by Pool and Cash, reproduced by Kennon et al., incorrectly shows the front side of Leinster House with second-story window pediments arranged almost exactly like those on the first-story front of the final White House.

Because of this inaccurate detail which was reproduced in Hoban’s designs, I think it quite possible that Hoban had a copy of this 1780 book, which he would have used to refresh his memory about Leinster House’s architecture when designing the original 3-story WH plan. Moreover, judging by the floorplan and partial side elevation which survive of his original three-story concept, it is quite possible that the Pool and Cash elevation is very close to what Hoban originally had in mind before budget costs forced a reduction in scale of the project.

I always thought that Hoban was indeed working from an architecture book and not from personal study of Leinster House, but I don’t recall seeing the book named.