Until building-code restrictions forbidding continuous cornices and roof planes were adopted after the Great Boston Fire of 1872, complicating if not discouraging the practice, Back Bay architects often designed adjoining houses as a larger related composition. None were more urbane than these four houses, surviving from the original five, at 403–409 Beacon Street. Lest anyone miss the Parisian reference of the casements at number 409 (unusual for those double-hung days), the delicate castiron balconies spanning the facades of numbers 403–407 describe an unmistakably Gallic fleur-de-lis motif. Advancing and receding pavilions are answered by the inverse-pilaster effect of the brick coursing's idiosyncratic vertical recessed panels. Like many of his countrymen, English-born George Snell was clearly a Francophile; of his partner James Gregerson, alas, nothing is known, other than that he once lived at 403 Beacon Street.