Item #6797 Cream Raising and Butter Making. A explanation of the process of cream raising by the cold, dry air method, as employed in the Ferguson Bureau Creamery; also the concussion method of churning, whereby the butter is obtained in granular form, and is wholly freed from butter milk, by the use of the Ferguson Concussion Churn, and Improved Butter Worker. Trade catalogue – Butter, Ferguson Manufacturing Co, Vt. Burlington.