Aesthetics have always been part of weapon making. From the moment man became tool maker he felt the need to embellish. The stone-age axe, shaped and smoothed beyond function need, the sculptured power of the Greek helmet, the beautiful lines of the Spitfire. Display of aggression needs aesthetics and there is something in us all that states, if it looks good it works better. Yet the submarine is the only weapon where aesthetics plays no part, it is designed not to be seen. The pursuit of invisibility has no need of art; the submarine is the aesthetic Anti-Christ.

It was the lifeblood of a city. For century shipbuilding sustained Glasgow - fed it, clothed it, housed it, and in return Glasgow gave its men. Hundreds of thousands of them - to be sacrificed in the cathedrals of the Shipyards, to the gods of the battleship and liner. They made their libations in sweat. Their prayer books were the pay slip and the time sheet; their litany the poetry of the imperial measurement. Anyone who thinks this a somewhat fanciful rendition of an old and well-worn story - the religious analogy a little precious - should visit Iron, Tom McKendrick's extraordinary new display at Glasgow's Collins Gallery.