Indeed the surviving instruments (the earliest is of 1556), as well as William Bourne's drawing of 1567, show the four quarters of the heavy plate as open, to lessen wind disturbance.
Isixhobo sokuphila ngenene (ngaphambi konyaka wewaka linye linamakhulu amahlanu linamashumi anesithandathu) kanjalo nemizobo kaWilliam Bourne, ngonyaka wewaka linye linamakhulu mahlanu anamashumi anesixhenxe ebonisa izahlulo ezinepleyinti enzima njengokuba ivulekile kumoya ophazamisayo.