In former hot air engines it was impossible to prevent the valves from leaking ; this difficulty seems to be overcome in this one, as it has been running for several monthi without requiring any ...

If hot-air engines and inflammable gas engines fail as yet to furnish power comparable to .hat which steam affords, without a very disproportionate increase of bulk, and for high powers fail to ...

The Federal Aviation Administration has ordered airlines to address a problem affecting Rolls-Royce-powered Boeing 757s that ...