John Sloan:
Hourglass (O-1)
John Sloan:
Astrolabe (O-2)
John Sloan:
Obelisk (O-3)
John Sloan:
Candleclock (O-4)
John Sloan:
Sundial
John Sloan:
Waterclock
John Sloan:
Cesium
John Sloan:
Four GPS Antennas
John Sloan:
Lady Heather
John Sloan:
Cesium NTP Monitoring Tool
John Sloan:
Sophia