The Editor wishes to express his gratitude and appreciation to the following, to whom he is indebted for much valuable assistance in the form of illustrations and special information:

• Addressograph Co.
• “The American Boy.”
• American Chicle Co.
• American Cyanamid Co.
• American LaFrance Fire Engine Co.
• American Locomotive Co.
• “American Magazine.”
• American Pin Co.
• American Telephone and Telegraph Co.
• Armour & Co.
• Baldwin Locomotive Works.
• “Baltimore American.”
• Bethlehem Steel Co.
• James Boyd & Brother, Inc.
• Brunswick-Balke-Collender Co.
• Burroughs Adding Machine Co.
• California Fruit Growers’ Exchange.
• California Redwood Association.
• Chesapeake and Potomac Telephone Co.
• Colt’s Patent Fire Arms Manufacturing Co.
• Columbia Graphophone Co.
• Columbian Rope Co.
• Common Sense Gum Co.
• Consolidated Fire Works Company of America.
• Curtis Aeroplane Co.
• Curtis Publishing Co.
• Cutler-Hammer Manufacturing Co.
• Diamond Crystal Salt Co.
• G.M. Dodge Co.
• Eastman Kodak Co.
• Endicott, Johnson & Co.
• “The Field.”
• “Fire and Water Engineering.”
• Ford Motor Co.
• Gatchel & Manning.
• General Electric Co.
• General Motors Truck Co.
• Gloucester (Mass.) Board of Trade.
• B.F. Goodrich Co.
• Haynes Auto Co.
• Hendee Manufacturing Co.
• R. Hoe & Co.
• George A. Hormel & Co.
• Hotpoint Electric Heating Co.
• Hudson and Manhattan Railroad Co.
• Indiana Steel Co.
• Ingersoll-Rand Co.
• International Harvester Company of America.
• International Silver Co.
• Jacobs & Davies, Engineers.
• Lake Torpedo Boat Co.
• McClure Co.
• Merganthaler Linotype Co.
• Monroe Calculating Machine Co.
• New York Central Railroad Co.
• New York Edison Co.
• Niagara Falls Power Co.
• Otis Elevator Co.
• The Panama Canal, Washington Office.
• Pennsylvania Railroad Co.
• The Philadelphia Museums.
• Plymouth Cordage Co.
• Nicholas Power Co.
• Pyrene Manufacturing Co.
• “Railway Age Gazette.”
• Mr. George A. Reading.
• Remington Arms-Union Metallic Cartridge Co.
• A.I. Root Co.
• “Scientific American.”
• “Scribner’s Magazine.”
• Standard Steel Car Co.
• Capt. Charles H. Thompson.
• Mr. Charles L. Trout.
• Mr. Harold L. Tuers.
• United Shoe Machinery Co.
• United States Rubber Co.
• Waltham Watch Co.
• Westinghouse Co.
• Winchester Repeating Arms Co.
• Wilcox & Harvey Mfg. Co.
• “Winston’s Cumulative Encyclopedia.”