One of the perquisites of my work is getting to poke around in the attics and basements of old buildings.  Along with mummified squirrels and decades of dust, weird and elegant things occasionally pop up. Last weekend I was helping my friends Anne and Paul evaluate the wisdom of buying a particular 2-family house in Arlington, MA.  The house was unremarkable, but the attic had a couple of treasures:   These two wooden toilet tanks served the first and second floor bathrooms.  They were reportedly located in the attic to ensure that there was enough pressure to clear the un-optimized bowls of 1913. The house also had the most elegant retraction mechanism for an attic stair I’ve ever seen.     There were a…