Show aane americans ricas best known vehicle silvery shenandoah has been watched by mil lions of people washington D 0 already americas best known vehicle ls is tha shenandoah says a bulletin of the national geographical society from its washington D C headquarters hundreds of thousands have seen some come of the count rys crack trains and giant liners literally millions have watched the silvery shenandoah steal silently across the sky eky says a communication to the society so clety incidentally the shenandoah and the 3 ate are not strictly speaking dirigibles they are technically called rigid airships the shenandoah comprises many wonder stories of modern science lance sc its length feet Is two thirds that of tho the leviathan yet its weight of only 87 tons Is a tiny fraction of the levi athans tons hangar near capitols size to house it and a bigger sister ship to come a hangar was built in a clearing of the new jersey woods which building Is feet longer than the united states capitol building just two feet less than the capitols widest part and more than two third as high the sliding doors at one end edd weigh 1300 tons As the airship floats mysteriously overhead it looks like a magnificent cigar wrapped in tin foil with six tiny baskets suspended from it inside the covering are 20 great gas bags with a total gas capacity equal to the cubic contents of a train of freight cars these are interspersed with from 40 to 78 gasoline tanks and a complement of one ton water tanks this equipment Is supported by a metal framework which Is a veritable maze of girders struts and beams there are strut alone in the intricate design it Is for this metal framework that mint Is used nn an allo so light and strong that a girder 16 feet long can be bala balanced aced on ones onea little finger yet if the tips are placed on blocks it will bear the load of eight men sitting upon it in one of its six cars tb lb a pho te graphic laboratory so taint aution picture reels and photographs may be developed on board and the pictorial tory story of a flight be ready when the ship h ap lands landa or even thrown overboard by parachutes at designated places another car has a soundproof sound bound proof radio compartment with a powerful sending apparatus and telegraphic ments I 1 the most astonishing mechanical contrivance on the shenandoah Is the newly installed water recovery apparatus pa ratus which replaces the gasoline burned with an equivalent weight of water and thus saves the of at precious helium you will recall from your chemistry courses that gasoline consists of hydrogen and carbon when gasoline is burned the carbon combines wa with th some of the oxygen from the air to form carbon dioxide and the hy by drogen with other forms weter water notice in cold weather that their exhaust pipes steam occasionally the moisture freezes freeze and forma a ring on the tee vent the apparatus for recovering water on the shenandoah consists of several tiers of long light pipes exposed to the cooling air so BO that tho the super heated steam condenses and fills water tanks this manufactured water compensates pen sates for the weight of the allne consumed formerly as fuel was burned the ship grew lighter and tended to rise therefore the gas expanded and it was necessary to release enough helium to equalize equall ze the lift of the gas to the weight of the ship even though helium cost has been brought from a luxury price of 81 for a thousand cubic fl feet the amount the shenandoah had to valve on long trips was an expensive operating item on its ita st louls louis visit for example cubic feet of helium had bad to be the wa ter recovery device means a saving on one such trip of enough to pa pay y for the experimentation and installation stal lation laUon of the cie mechanism |