That pic is almost exactely how I chained my goat when I first got her. Her chain was about 2 feet or so longer, but same concept. And I used a cinder block. She could drag the block to move around a bit but it was too heavy for her to take off with in. Didn't keep her on it as long as your saying though, just enough to train her to stay. You can't fence goats, you have to teach them that being in the fence is a good life. When I tried to tie her to a tree she got tangled and almost strangled herself daily. The short chain tied to a weight is about the best way to do it.