Ron also mailed Mr. Greenwood following Photo of Atreus-Dome.
Treasury of Atreus-Dome
A very poor photograph, I'm afraid. They were closing the exhibit so there was no time to set up, even to focus manually (it was too dark for auto focus). I just set the flash and fired.
This is a massive tomb from about 1300 BC, located near Mycenae. You can just about see the "beehive" shaped dome. Question. Is this a dome? If so, then they existed before the Romans.
Mr. Greenwood checked a Penguin Books published in 1978, "Structures" written by J.E. Gordon, Prof of Univ. of Reading. (in Japanese translation, Library Serial No.5) In his book, very primitive vault of Tilince in Mycenae constructed in BC 1,800 were exhibited. If the triangular big stone having relief of lion on it of Lions' Gate in Mycenae is removed, it looks exactly same. In this structure, big stones are piled in a way so that each stone slightly shift toward center of the vault. This method, however, causes bending moment in each stone and causes tensile force in upper portion of each stone. To reduce tensile force, each stone need to be thick enough. Roman type arch however uses wedged shaped stone. In this case, only horizontal compression force is caused inside each stone. An advantage of Roman type is that you can use small stone and easy to make it manually. A very primitive dome which Ron has found might have similar structure like the vault of Mycenae.
27/06/02