Wallace had an impressive collection of testimonials including ones written by Playfair, Dugald Stewart, Maskelyne, Charles Hutton, William Herschel and Maseres . Leslie also wrote a letter of support.
Wallace nagkaroon ng isang kahanga-koleksyon ng mga testimonyal kabilang ang mga nakasulat sa pamamagitan ng Playfair, Dugald Stewart, Maskelyne, Charles Hutton, William Herschel at Maseres. Leslie din wrote isang sulat ng suporta.