Fry bacon, set aside. Simmer potatoes til nearly done. Drain, reserving potato water. Saute onions, and celery in leftover bacon grease, til soft. Add butter and melt. Add flour and stir. Add clam juice and half and half. Stir til smooth and thickened. Add seasonings. Potatoes and clams. Simmer til flavors have merged. Do not allow to boil.