<Tr> <Td_colspan="6"> The Waltons shelter a deaf girl (Erica Hunton) left on their back porch by her mother because her father insists on institutionalizing her . While they search for her family, they start teaching her sign language, which she uses to help Elizabeth when an emergency arises . </Td> </Tr> <Tr> <Th> </Th> <Td> </Td> <Td> "The Carnival" </Td> <Td> Alf Kjellin </Td> <Td> Nigel McKeand </Td> <Td> September 21, 1972 (1972 - 09 - 21) </Td> </Tr> <Tr> <Td_colspan="6"> A traveling carnival comes to Walton's Mountain, but the children choose to sacrifice the money they had saved for it so that Grandma can replace her broken glasses . When the troupe becomes stranded by their dishonest ringmaster, John and Olivia allow them to stay temporarily in their barn, and the family is rewarded with a private show . </Td> </Tr> <Tr> <Th> </Th> <Td> </Td> <Td> "The Calf" </Td> <Td> Harry Harris </Td> <Td> Jim Byrnes </Td> <Td> September 28, 1972 (1972 - 09 - 28) </Td> </Tr>

How many episodes of the waltons are there