It is not subtlety or musicianship that makes popular song, but a good gimmick or punch-line in every verse. So, too, with a building that becomes the rage of the hour – whatever professional craft and architectural skill Louis Kahn may have invested in every part of the Richards Medical Laboratories in Philadelphia its uncontrollable success depends on just two simple and superficial things: its picturesque silhouette of clustered towers, and the fact that those towers are mostly for services. It is not easy to say which of these is the more important consideration, because they appear to have run as closely together in Kahn's mind as in that of his admiring public.

Taken in bulk, this busy assemblage of expressively articulated vertical masses and comparatively fragile looking horizontal truss-work, complex and irregular in phan, is a reaction against the smooth anonymity of the Mies tradition, that would have wrapped up the whole project in one exquisite crystalline box, and this reaction clearly chimed in with the increasingly picturesque mood of the post Brutalist world (Kahn is one of the Brutalists’ favourite architects). But, in addition, this is a building whose functions demand s formidable array of mechanical services (to clear off toxic atmospheres from the laboratories) and Kahn has expressed this with an equally formidable array of brick monoliths crowding closely about the glass boxes with the laboratories in them.

Nothing could make more clear or more dramatic Kahn's concept of the servant spaces (towers) and the served spaces (laboratories), and to a profession increasingly concerned with the problem of packing mechanical services bigger and more complex every year - into or around their designs, the Philadelphia towers were triumphant proof that the solution of the services problem could be monumental architecture. One pointremained to be resolved however: was it architecturally honest to make something so very monumental (‘Duct-henge’ was the ribald estimate) out of anything so transient and changeable as services, here today and obsolete tomorrow? Might not Zanuso’s clip-on solution at Merlo be more honest while no less eloquent?

Banham R. Age of the Masters: A Personal View of Modern Architecture. Harper & Row., 1975. P. 86-87.