Cart Continue Shopping “(Robert Smithson, Massimo Antonaci). John Weber Gallery, New York, January 11 – February 8, 1997: Robert Smithson. Issues of Entropy / Massimo Antonaci. “Has Become the Keystone of the Arch”” has been added to your cart. Product Price Quantity Total × (Robert Smithson, Massimo Antonaci). John Weber Gallery, New York, January 11 - February 8, 1997: Robert Smithson. Issues of Entropy / Massimo Antonaci. "Has Become the Keystone of the Arch" $20.00 1 $20.00 Coupon: Cart Totals Subtotal $20.00 Shipping Flat Rate domestic: $4.99 Total $24.99 Proceed to Checkout