application as described further below the mesh size is such that the gaps are no larger than a maximum distance permitted for preventing flame propagation for the specific flammable fluids used this aspect of the invention will now be described in more detail it is known that flame fronts propagate outward from their ignition source to propagate however a flame requires at least a certain amount of space to do so if there is insufficient space adjacent the flame the flame cannot propagate in that direction the amount of space required depends on the flame characteristics which is dependent in part on the fuel burned therefore if the mesh size is correctly chosen for the pertinent flammable fluid such that the gaps in the wire mesh are small enough flame propagation can be prevented thus the flame arresting blanket of the present invention does not prevent the flammable fluid from igniting but does prevent the flame from propagating beyond the mesh as mentioned flame arresting blanket 12 is made of a porous material having a multiplicity of voids defined therein however none of the voids exceed the maximum gap for stifling flame propagation the specific internal configuration of the fibrous network of flame arresting material is not necessarily critical as long as the maximum air gap length is not exceeded along any path away from the engine towards the outer surface of the flame arresting blanket 12 preferably the maximum air gap in the material is not exceeded in any direction three dimensionally speaking within flame arresting blanket 12 although in light of the present disclosure one skilled in the art will appreciate that exceeding the maximum air gap in a.