Wash and scrape a small carrot; cut in quarters lengthwise; cut quarters in thirds lengthwise; cut strips thus made in thin slices crosswise. Wash and pare half a turnip, and cut and slice same as carrot. Wash, pare, and cut potatoes in small pieces. Wash and scrape celery and cut in quarter-inch pieces. Prepare vegetables before measuring. Cut onion in thin slices.
Mix vegetables (except potatoes), and cook for ten minutes in four tablespoons butter, stirring constantly. Add potatoes, cover, and cook two minutes. Add water, and boil one hour or until vegetables are soft.
Beat with spoon or fork to break vegetables. Add remaining butter and parsley. Season with salt and pepper.