Graham Bell's letter to parents on how to use telephone fetches $92,856

London, Jan 20 (ANI): The letter which Alexander Graham Bell wrote to his parents in 1878, which includes rare and elaborate drawings of the telephone he invented has been sold for more than 92,000 dollars, an auctioneer claimed.

The letter instructs the Scotland-born Bell's parents on how to ground the telephone to avoid harm from lightning strikes.

He instructs them to run a sturdy copper wire from their house to the duck pond and bury it there.

"If you have a good connection with a permanently moist stratum of earth, you need never fear lightning and your posts will be safe," the Telegraph quoted Bell as writing.

The letter was written two years after Bell obtained the patent on the telephone and made his first call to his assistant, Thomas Watson.

Bidding on the letter offered by RRAuction began in December and ended Wednesday, with the top bid coming in at 92,856 dollars. (ANI)