41. The first gunpowder weapons usually consisted of metal tubes tied down to wooden staves. 42. "In ` Das Boot,'we had the crew stranded in a metal tube under the sea. 43. The metal tube shields the conductors from electromagnetic interference. 44. It had a duralumin sheet hull and the tail was made of framed metal tubing . 45. The aircraft carriage is built from bolted metal tubing . 46. Beyond it, two arms hold the metal tube in place as the 72 chains unfurl. 47. First the bushing, a tapered metal tube , is inserted in the end of the hose. 48. The receiver proper is a square metal tube which partly nestles inside the plastic handgrip. 49. The fuselage is made of metal tubing covered with fabric, and the wing is plywood. 50. The empty metal tubes would subsequently be collected in a pan located under the weapon.
