These two battery tops were found a long way from home in a junk shop in in South Australia, I have seen a fair number of battery jars, it seems they survived well because they are made of thick glass and are quite robust, the tops on the other hand are quite fragile and easily destroyed I did not know what I had found when I first came across them, but have been assured that they were used to power very early remote telephone lines. Maybe some-one could help with a bit of info. Have a good one. Luke