"You've changed the wiring on the disk, haven't you?" asked Ned, who knew a little about electricity. [Illustration: "I Want to Try Alternating Current."] "I want to try alternating current instead of direct and see if doing so won't improve it. Dad suggested that. What is it, Koku?" "Boy bringum letter for Master. Say must put name on book." The man held out an envelope and pad. "It's a radiogram. Sign for me, Ned, will you?" Tom ripped open the envelope and glanced over the message. "Bad news?" asked his chum, seeing a changed expression on the inventor's face. [Illustration: Tom Ripped Open the Envelope] "I should say so. Here, read it yourself. We might just as well forget the whole telescope idea, that's how bad it is!" Ned took the sheet, which Tom had crumpled, spread it out on the desk, and read as follows: "Regret inform you was compelled to jettison your cargo last night in bad storm to save ship. Approximate location four miles due east Port Baracoa, Cuba. Salvage boat take position at apex isosceles triangle 27.6 degrees with lighthouse and summit hill a mile to the south." "(Signed) A. Mawson, Captain S.S. Perry." [Illustration: "Was Compelled to Jettison Your Cargo."] "Say, Tom, that IS tough, having your meteorite thrown overboard!" exclaimed Ned, rereading the message. "All your work wasted and your marvelous invention junked--" "Not yet!" broke in the young scientist grimly as he grabbed the telephone from his desk. "Hello, operator, get me long distance, please." [Illustration: Tom Grabbed the Telephone] "What are you going to do?" asked Ned excitedly. "Get divers," replied Tom as he waited. "I'm going to recover that meteorite or know the reason--Oh, hello! Yes. I want the main office of the Neptune Salvage Company in New York City. No, I haven't the address. Yes, I'll hold the line. "These people are experts," he told his chum while waiting for his call to be put through. "If the stone isn't in too deep water they'll be able to raise it if anyone can." [Illustration: "I'm Going to Recover the Meteorite."] "But how can they ever find it? Seems to me it'll be like hunting for the proverbial needle in a haystack, only more so!" "Not quite that bad. Captain Mawson gives what seem to be pretty complete directions. You might try getting any further data the man may have." [Illustration: "Captain Mawson Gave Directions."] Unfortunately for Tom, as he learned in the next two hours, the Neptune Company and other salvage concerns he called were very busy and could not spare a barge of the required size. Moreover, Ned could get no more information, when he finally contacted the freighter, than her commander had given already. "Why doan yo' tak' yo' submarine boat down dere, Massa Tom?" asked Eradicate as he served luncheon to the young inventor, his father and Ned. "Ah 'members we once got some treasure off'n de bottom ob de sea dat way." [Illustration: Eradicate Served Luncheon]