The Ring and Thimble as answered well below but read above the picture for some source material from Treeve which explains their existence!
The Ring and Thimble
I have just found my mother's typewritten presentations, when she was studying at Miss Wesley's Secretarial School in South Parade.
The item is dated 11th October 1937, she was 15 years of age.
She has included the story of The Ring and Thimble.
I use her words as written.
Before the Bolitho's the most important parts of the Penzance Borough,
there was a man named Price who owned those parts.
This man had a daughter and he was very fond of her, so he gave her a diamond ring for her birthday.
One day, she went out for a ride on her horse,
and it got frightened at the top of Chywoone Hill, and it threw the girl off, and the consequences were fatal.
On bringing her home, the father found the ring was missing from her finger, so he sent out orders to all his men to search for it.
It was not until after the burial, that one of the men thought of searching at the scene of the accident,
and there, he found the ring, and also a thimble.
How the ring got there is common knowledge,
but as to the thimble remains a mystery to this day.
The father then thought it would be a memorial to his beloved daughter if he had stones cut to resemble the ring and thimble.
Anyone having walked up Paul Hill and keeping on the road to Sheffield will see these two stones by the roadside.
Raymond Forward