SAN FRANCISCO, July 3, 1937 (UP) -- Miss Earhart's husband, George Palmer Putnam, maintaining a ceaseless vigil at Oakland airport, was not convinced today that the voices heard by amateur radio operators were those of either Miss Earhart or Captain Noonan, her navigator.
He also was not certain that the plane actually had sent out earlier dot and dash signals picked up by Coast Guard stations, by the British cruiser Achilles and the freighter New Zealand.
"I would be tremendously cheered if these reports were true," he said, "but the plane is obviously down somewhere, and, being down, I am afraid its radio would be completely out of commission."
Guarding against emergency, Miss Earhart and Captain Noonan had taken along a large supply of rations-condensed food such as malted milk tablets and chocolate, enough to last for several weeks. Also aboard was a "rebreather outfit," a device which manufactures drinking water through the simple means of condensing human breath.
A two-man rubber raft was also on board, the plane, together with flares and a bright orange kite, which could be sent aloft to attract attention.
Mr. Putnam said the plane itself could stay afloat for a long time.
The position of the lost plane was not definitely fixed, but was believed to be perhaps about 100 miles north of Howland Island.
Miss Earhart apparently overshot Howland Island, her objective, and then came down at sea when she exhausted her fuel. The plane is a land ship, but was constructed to stay afloat indefinitely with its retractable landing gear. The empty gasoline tanks, as well as the wings and fuselage, were built with this contingency in mind, but exceptionally heavy seas might soon smash and sink the plane.
Miss Earhart's repeated SOS messages were picked up in the United States and as far off as Australia. The best guess that could be hazarded from the plane's messages and allowing for known currents in that vicinity placed it about 100 miles north of Howland Island.
The Coast Guard cutter Itasca was patrolling the waters off Howland Island from the hour it became apparent to Miss Earhart that she was going to be forced down at sea.
The British cruiser Achilles, which was first to pick up the Earhart signals, reported that after hearing the SOS the plane asked:
"Give us a few dashes if you hear this-KHAQQ."
An amateur radio operator in Los Angeles reported that he heard Miss Earhart's voice distinctively this morning and two other California operators likewise picked up her distress signals and her call letters, KHAQQ.
"It was Miss Earhart all right," said Walter McMenamy. "I know her voice very well. She just keeps repeating SOS over and over. A little while ago she said something else, but I could not make it out.
"She can't use code herself, so I assume Noonan is busy or asleep, or something. Her voice sounded pretty good. Not scared at all-she never sounds that way."
Mr. McMenamy said he intercepted signals from the plane which he thought might be Miss Earhart's navigational reading.
"It was 179 and what sounded like 1.6," the amateur operator said. "That position would be considerably more than 100 miles off Howland Island."
Earlier code signals, presumably from Mr. Noonan, came in steadily every fifteen seconds. Shortly after 7 A. M. New York time, signals became loud enough to be picked up by a loud speaker and relayed over telephone. The radio operators attributed this to the fact that it was dark the entire distance and there was no longer daylight static.
Steady and clear-cut at first, the calls became ragged and jerky hours later, as though the hand on the key was growing nervous under the strain, the radio men said.
"It's the most jittery code I ever heard," McMenamy commented.
The station operated by Mr. Pierson, short wave radio engineer, and Mr. McMenamy appeared to be the only mainland wireless steadily receiving signals from the plane.
This station is one of the few equipped with an amplifying, directional, inside-beam antenna, which permits long-range reception, it was explained.
Lieutenant S.K. Johnson, of San Francisco Coast Guard headquarters, said that the Itasca at Howland Island had identified weak radio signals as coming from Miss Earhart's plane.
"The signals are so faint," Lieutenant Johnson said, "that the Itasca operator is unable to determine the plane's location."
He added that the signals were being heard on all sides, even down in Sydney, Australia.
"But, he said, "they are weak and there is no way of running them down."
The signals were on international airplane frequencies of 31.05 and 62.10 kilocycles, and also on the international distress frequency of 500 kilocycles.
Meanwhile the U. S. S. Swan was ordered to proceed to Howland Island from a point between that island and Honolulu. Naval authorities at Honolulu also said the U. S. S. Colorado would leave Pearl Harbor shortly for Howland Island arriving there within two and a half or three days. The Colorado carries three planes which would be used almost constantly in searching for Miss Earhart.
The last word from the plane while it was in flight was picked up at 12:55 P. M., P. S. T. (4:55 P. M. New York time) yesterday by the Itasca, stationed at Howland Island. The Itasca had only heard the plane's signals.
Early today Admiral William D. Leahy, chief of naval operations in Washington, ordered the commandant of the Honolulu district to make all naval facilities available in the search. The Admiral acted when Mr. Putnam appealed to the Navy Department for aid.
The supposition was that by some slight miscalculation in navigation, Miss Earhart's plane had missed the island, which could not be seen even from a plane, 100 miles away. It never has been visited by air.
The island was the only available landing place. It is about two and a half miles long and less than half a mile wide. The Itasca had been stationed there with fuel for Miss Earhart's plane.
Just fifty-six minutes before her final radio message, Miss Earhart had estimated in another radio contact that she was about 100 miles from the Itasca, but was unable to give the relative bearings. Coast Guard operators estimated that the plane might be found floating within 100 miles of the island, possibly northwestward.
Continual radio messages were being broadcast to the plane from the Honolulu Coast Guard station and from the Itasca. Both voice broadcasts and signals were sent. The signal is the letter "N" which the plane could pick up for direction with its Bendix finder.
Only one steamship, the Matson Line's S.S. Monterey, was known to be in the area. The Monterey was bound for Suva and some distance off Miss Earhart's route.
The Itasca had fuel for a six-day search. The U. S. S. Ontario, which had been stationed half-way between Lae and Howland in case of emergency, was equipped for a shorter search and was farther removed from the scene.
Navy planes out of Honolulu would have to fly directly to Howland, search as long as their fuel supplies permitted, and then go to Johnstown Island to await a naval tender which would bring fuel. Howland is 1,800 miles southwest of Honolulu. Johnstown is 600 miles from Howland, in the direction of Honolulu.
The "flying laboratory" was powered with two Wasp engines that were capable of developing 550-horsepower and 220 miles an hour top speed.
Its fuel capacity was 1,151 gallons, and its cruising range 4,000 miles. Cost of the plane and its elaborate equipment was paid by Mr. Putnam and by Purdue University, which was interested in the scientific aspects of Miss Earhart's flight.