The purpose came to me later when I changed my front door to a new one and combined these two thing with some hardwood I got from a neighbor (He had it lying behind his house for years, used to be the base of his garden shet) and the legs of our old pine dinner table: These had to be transformed to a very sturdy garden side table.
Here is how I did that (although I might have missed some steps because I didn't took pictures of every step.)
Step 1: The Materials
Another day I got these big and heavy hardwood beams from a neighbor. They had a routed notch/angle (?) in them, in which the stone plate perfectly fitted.
My old merbau wood front door provided me the rest of the frame and last I used metal angles and the legs of our old diner table made out of pine. This table has been used in the garden for a few years on the place where this new table is standing now but it was to big for this small roofed space. The table top itself I used for another interesting project about which I will make another Ible later.
Step 2: Measurement and Sawing
I had to measure the angles in the corners and used a handsaw to cut them of because I was a pain to use the circle saw with this hardwood. I don't know what kind of wood it is but I think concrete fruits grew from it when it was still a tree!
For the rest I think the pictures speak for themselves.
Step 3: Assembling
Step 4: Finishing and the End-result
I hope you like it as much as I do. If you do don't hesitate to take a look at my other Instructables and follow me.