Doris I made that ball years ago using a bowling ball and a weatherproof glue that was quite smelly. I don't remember the name of the glue and am not sure if they still make it. I had to do small sections at a time as the pennies would slide out of place until the glue would set up. When it was done I didn't like that I could see parts of the bowling ball so I put a second layer of pennies covering up all of those areas. When it was complete in order to keep it shinny I sprayed it with a clear outdoor uv proof coating. Mine has stood up well only losing a penny or two I do bring it indoors in the winter to help preserve it.
Thanks Doris and lilylady for the comments on my garden.
Here are a couple of daylily photos
Kings Favor
Lights of the Evening
