THE CRUISE 



On May 1, 1928, the seventh cruise of the Carnegie 

 began. Whistles roared from the harbor craft, and 

 pleasure boats jockeyed for position to escort us down 

 the Potomac. At midnight we reached the mouth of the 

 St. Mary's River in Chesapeake Bay, and anchored till 

 dawn. We were to spend four busy days here, "swing- 

 ing ship," to be sure that our magnetic instruments and 

 standard compass were not influenced by the new ocea- 

 nographic equipment. A magnetic station had been set 

 up on shore where simultaneous magnetic observations 

 were made. To ensure ideal conditions for the land sta- 

 tion, a magnetic survey of both sides of Chesapeake Bay 

 had been completed a few days previously. Six "swings" 

 of the ship on different headings were made, before 

 everyone was satisfied that all was well. 



The radio outfit was given its first trials here. 

 Schedules were made with the Naval Research Labora- 

 tory and with headquarters of the American Radio Relay 

 League. And throughout these four days, the atmospher- 

 ic-electric instruments were being compared with simi- 

 lar ones ashore whose accuracy was well known. 



The days spent here in the St. Mary's River had 

 given the new observers an opportunity to become ac- 

 quainted with their new duties. They now knew what a 

 long day's work was involved in swinging ship, a pro- 

 cedure we were to repeat in many parts of the world. 

 They learned the technique of intercomparison of instru- 

 ments with those ashore, for in most of the ports of call 

 this was to occupy a large part of their time--especially 

 where there were permanent observatories like those in 

 Germany, Peru, Samoa, and Japan. 



At dusk on May 5, all hands were summoned to heave 

 up the anchor for the short trip to Hampton Roads--our 

 first passage under sail. A stiff, steady breeze from 

 astern bowled us along in grand style. Although we were 

 not carrying full sail, we had the rare satisfaction of 

 overtaking several steam vessels. 



We were anchored off Newport News by eight o'clock 

 next morning, and were greeted at once by "bum boats," 

 little launches which were to be our inseparable com- 

 panions in every port. They offered laundry service, 

 taxis, provisions — everything we needed, and some 

 things we did not. 



Everyone was impatient to put to sea, so it was a 

 great disappointment that we were forced to go into dry- 

 dock here. The oscillator of the sonic depth finder re- 

 quired some changes, and Mr. Russell of the Navy Yard 

 in Washington had come personally to supervise the 

 work. 



On May 10 we were towed out into the Roads, and 

 set sails, while photographers on the tug made pictures. 

 The breeze was just sufficient to give us steerage way. 

 We had cast off our last ties with shore, and were at last 

 headed for the open sea. Our last sight of land was Cape 

 Henry at sunset. 



It was a real relief to settle down to our ocean rou- 

 tine. The hectic past months gave place to as simple a 

 life as possible. Meal hours were so arranged that in 

 spite of their various duties, the staff could eat together. 

 The radio operator and atmospheric-electric observers 

 occasionally kept irregular schedules which made this 

 not always possible. The watch officers and the engineer 



had their mess in the wardroom forward; and the fore- 

 castle was served from the same galley. The deck force 

 was separated into two v/atches, as is usual on a sailing 

 ship; the men spending four hours on and four off, with 

 two "dogwatches" of two hours each between four and 

 eight in the evening. 



Our first morning out. May 11, was chosen for the 

 first magnetic station. The ship was now fifty miles off 

 tha coast and away from local disturbances ashore. At 

 sunrise the officer on watch calls the observers to the 

 bridge for the declination observation. When they are 

 assembled the ship's course is changed, if necessary, to 

 keep the foresail from hiding the sun. Captain Ault and 

 Torreson make readings of the marine collimating com- 

 pass; Erickson measures altitudes of the sun with his 

 sextant; and Scott enters each reading on special forms, 

 with a time record for each observation. From these 

 measurements we could tell how much the "variation" 

 of the compass had changed since former cruises. 



After breakfast is over, and when time sights on the 

 sun have been made for longitude, the observers take 

 their places at the magnetic instruments in the domes. 

 Soule stands at the earth inductor; Torreson sits in the 

 control room on the quarter-deck; and Paul reads aloud 

 the heading of the ship from the standard compass in the 

 chart room. This allows Soule to keep the rotating coil 

 properly oriented. As Soule places the coil in various 

 positions, Torreson reads the ammeter or potentiometer 

 in the control room. From here he also starts and stops 

 the constant-speed motor which rotates the coil. These 

 observers determine the "dip" or inclination of the 

 earth's magnetic field. 



Meanwhile, Scott is in the after dome at the deflec- 

 tor. He places magnets of known strength near his com- 

 pass and reads off their effect on it. Jones makes simul- 

 taneous readings of the standard compass in the chart 

 room, and records for Scott. These two men measure 

 the strength of the earth's magnetic field. 



The afternoon is occupied in calculating the values 

 for the magnetic elements. The observers were fur- 

 nished special forms for recording, and these were so 

 printed as to make the necessary tabulations as simple 

 as possible. The formulae used in computing appeared 

 in these, together with space for entering data derived 

 from tables. By using these sheets it was practically 

 impossible to overlook essential control records, such 

 as air temperatures and chronometer readings. It is 

 very easy to make these omissions when the observer's 

 attention is directed primarily to the operation of the in- 

 strument itself. 



For some of us the time-keeping on board was quite 

 confusing at first. The ship's routine was operated on 

 Local Apparent Time, with a resetting of clocks every 

 morning at eleven. Many records were kept on Local 

 Mean Time, others in Greenwich Mean Time. Then 

 there was 75th Meridian Time for certain radio sched- 

 ules, while a Sidereal-Time chronometer later became 

 part of our equipment for gravity observations. In addi- 

 tion, for the most accurate time-signal comparisons, an 

 "offset chronometer" was added, that loses one second 

 in sixty-five of mean time. 



After the evening time sight and the declination 



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