part of pickelhaube

[Polonez]

hello,
last week i found something interesting on a WWI battelfield. It looks exactly like a "ball" that is on artillery pickelhaubes. But it is full inside and quite heavy. My question is, is this a part of pickelhaube or something unimportant. Sorry for my bad english and quality of photos, my camera is broken now
http://img16.imageshack.us/i/zdjcie058so.jpg/
http://img685.imageshack.us/i/zdjcie057.jpg/

 

[911car]

No, this is not a helmet part. Who knows where it used to belong?... Furniture? Tool? Machine? Appliance?...

 

[Polonez]

i think so, it's too heavy and pickelhaube would fall from soldier's head thank you