Compare this test with the most strenuous conditions you will ever meet when motoring and you will appreciate what the Compensating Vapor Plug will do for you at the average touring speed over average roads and under slight variations in altitude. When the Compensating Vapor Plug can live up to our claims at mile-a-minute and better speed over the most terrible driving conditions imaginable, it can do far more for you than we claim. MONEY Compensating Vapor Plug Makes Starting Easy Instantaneous Results Simply Tap Hole in Manifold and Screw In Lifetime Guarantee No Adjustments Needed Never Wears Out Attached to Any Car in Five Minutes Make Your Test as Severe as Hammond's Put a Compensating Vapor Plug on your car at our risk that's what our 30 day money-back-il-not-satisfied offer means and then test it out over the roughest roads in your locality. Pick out the worst day possible for your tests and put a heavy load in your car. If you can find any worse conditions that these, do it. We are not limiting our claims for the Compensating Vapor Plug to ideal conditions. We don't want you to test its merit over boulevards or under sunny skies. The Compensating Vapor Plug is made on a scientific principle that is covered and protected by patents. Like all big successes, the Compensating Vapor Plug has its imitators; but these imitators cannot construct their devices under our principle without infringing our rights and inviting immediate prosecution, and the principle that we use is the  Only scientifically correct method of gaining a maximum saving in speed, power and mileage. 