Observatory

Claim 1

A ROTATABLE OBSERVATORY DOME CONSTRUCTION COMPRISING A SUPPORTING BASE AND A DOWNWARDLY OPENING HEMISPHERICAL DOME OF LIGHTWEIGHT SHEET MATERIAL AND COMPLETELY DEVOID OF INTERNAL BRACING AND SUPPORTS AND ROTATABLY END OF THE LATTER, AND ANNULAR TRACK MOUNTED ON UPPER END OF THE LATTER, AND ANNULAR TRACK MOUNTED ON SAID DOME WITHIN THE LOWER PORTION THEREOF, SAID ANNULAR TRACK BEING OF L-SHAPED CROSS-SECTION HAVING VERTICALLY AND HORIZONTALLY EXTENDING FLANGES, SAID VERTICAL FLANGE HAVING ITS OUTER FACE ENGAGING AND SECURED TO SAID DOME, VERTICALLY EXTENDING SUPPORT ROLLERS AND HORIZONTALLY PROJECTING GUIDE ROLLERS EACH CARRIED BY AND DISPOSED ABOVE SAID BASE ANS ENGAGING SAID ANNULAR TRACK AND RESPECTIVELY SUPPORTING AND CENTERING SAID DOME FOR ROTATION ABOUT A VERTICAL AXIS, SAID VERTICAL FLANGE HAVING ITS INNER FACE ENGAGED BY SAID GUIDE ROLLERS AND SAID HORIZONTAL FLANGE HAVING ITS LOWER FACE ENGAGED BY SAID SUPPORT ROLLERS, HOLDDOWN MEANS MOUNTED ON SAID BASE AND HAVING HORIZONTALLY PROJECTING MEANS OVERLYING OF THE LATTER FROM SAID AND PREVENTING DISENGAGEMENT OF THE LATTER FROM SAID SUPPORT AND GUIDE ROLLERS, SAID HOLDDOWN MEANS AND SAID SUPPORT AND GUIDE ROLLERS BEING HOUSED WITHIN SAID DOME LOWER PORTION.