What is the only safe method of using ether in an engine?

Using ether in an engine requires careful handling due to its highly flammable nature and volatility. A closed dispensing system stands out as the only safe method because it minimizes exposure to the ether vapors, thereby reducing the risk of accidental ignition and ensuring that the ether is contained and handled properly. In a closed system, the flow of ether is controlled, preventing leaks and allowing for safe transfer into the engine without exposure to ambient air, which could lead to hazardous situations.

On the other hand, open dispensing systems, direct injection, and spray applications can allow ether to escape into the environment. This increases the likelihood of creating flammable vapor concentrations, which can ignite easily, especially in the presence of sparks or high temperatures. Thus, utilizing a closed dispensing system is essential for maximizing safety when working with ether in an engine context.