In a medium skillet over medium heat, cook bacon, celery and onion until onion is translucent. Remove from heat and set aside.
In a large saucepan, melt butter over medium heat. Whisk in flour to form a roux, cooking until bubbly. Whisk in 1 jar of clam juice, until smooth. Stir in onion mixture. Pour in half-and-half, stirring constantly. Stir in clams, reduce heat and simmer 30 minutes.