Hubert, Pirrson & Company
Hubert, Pirrson & Company was a New York City architectural firm, founded by Philip Gengembre Hubert (1830–1911) and James W. Pirrson (1833–1888), which was active from c.1870 to 1888. It was later known as Hubert, Pirrson & Haddick from 1888-1898.
Source: Wikipedia — Hubert, Pirrson & Company (CC BY-SA 4.0)