REPORT ON ATMOSPHERIC ELECTRIC WORK 



43 



YOKOHAMA, JAPAN TO SAN FRANCISCO, CALIFORNIA, JUNE 24 TO JULY 28, 1929 



General. --Daily observations of the atmospheric- 

 electric elements have been made, with the few excep- 

 tions noted below. The light and contrary winds which 

 prevailed during the first week after leaving Yokohama, 

 and the fog, mist, and rain encountered in the higher 

 latitudes, made the period covered by this report unfa- 

 vorable for atmospheric-electric work on the whole. 

 Diurnal-variation runs were made on July 3 and 4 and 21 

 and 22. 



Potential-Gradient Recorder. --Twenty- six complete 

 days' traces have been secured, seventeen of which were 

 rendered abnormal by fog and mist. On some of these 

 abnormal days, hourly mean potentials of over 300 volts 

 (uncorrected to volts per meter) were recorded on 

 several occasions. Fortunately, during the stay in 

 Yokohama, the sensitivity decreased considerably, and 

 it is owing to this fact that complete records of the fog 

 effects were obtained. The recorder clock, which had 

 been showing a high and variable rate just before reach- 

 ing Yokohama, was cleaned and adjusted there and has 

 behaved remarkably well since. 



On June 30 the upper heating coil burned out and a 

 new one was fitted, the lead wires being renewed at the 

 same time. Leak tests and calibrations have been made 

 as before. 



Conductivity Apparatus 8A. --Values of conductivity 

 obtained near Japan, both before arrival and after depar- 

 ture, were abnormally low. During the periods of fog and 

 mist already referred to, the values were extremely low. 

 No instrumental difficulties have been encountered. 



The day before reaching Yokohama, during the heavy 

 weather of a typhoon, a block from one of the staysail 

 sheets dropped on the cowl of the air tube, breaking two 

 of the three horizontal supports of the cowl. Repair was 

 made in Yokohama, but the day after leaving, June 25, 

 a sheet of one of the staysails caught under the cowl, 

 bending it sideways and tearing the wire screen. A tem- 

 porary repair was made and it has remained effective. 



A more permanent repair will be made in San Francisco. 



Ionic Content Apparatus l. --On several days obser- 

 vation was impossible with this instrument owing to the 

 penetrating fog fouling the upper amber ring-insulator. 

 During the night hours of the diurnal-variation runs, the 

 insulation broke down from this cause. It is a question 

 whether a new design for the top of the air tube, similar 

 to that employed on the conductivity apparatus, would not 

 enable observations to be secured during light rains, 

 when, with the present arrangement, observation is im- 

 possible. 



Penetrating Radiation Apparatus 1. - -Daily observa- 

 tions have been made with this instrument and no diffi- 

 culties encountered. The Burgess "B" batteries used 

 for the plate potentials have given satisfactory service. 

 No renewal of the sodium in the drying tubes has been 

 made. 



Penetrating Radiation Apparatus No. 5503. — Com- 

 parison observations between this instrument and no. 1 

 have been made daily. Ehiring the diurnal-variation run 

 of July 3 and 4, no. 5503 was mounted on the starboard 

 side of the quarter-deck during the night hours. At 4h 

 on July 4 the fibers would not charge up; the instrument 

 was opened up in the warm cabin, where the heating 

 stove was burning, and it was found that the phosphor- 

 bronze leading strip had parted. A new strip was fitted 

 and the instrument has worked normally since. A sum- 

 mary of the comparisons between the two instruments, 

 especially with a view to determining the temperature 

 coefficient, has been made and the ratios for no. 5503 to 

 no. 1 have been plotted against temperature of 5503. It 

 appears that more observations are required at temper- 

 atures around 12° and also above 20° before an approxi- 

 mate temperature correction can be deduced. 



Nuclei Counter 5. --Except for four days when rain 

 prevailed, observations have been made daily. Values 

 have been generally low, averaging around 1500 particles 

 per cubic centimeter. 



SAN FRANCISCO, CALIFORNIA TO HONOLULU, HAWAH, SEPTEMBER 3 TO 23, 1929 



General. - -Between September 5 and 22, daily ob- 

 servations of the atmospheric-electric elements have 

 been made as previously. Some modifications of proce- 

 dure have been made, but care has been taken so as to 

 maintain a reasonable standard of accuracy and at the 

 same time to preserve the system of simultaneity of ob- 

 servation. Unusually calm weather with variable winds 

 was encountered between September 7 and 18, and very 

 low values of conductivity and ionic content were meas- 

 ured. The potential-gradient was correspondingly high 

 during this period. A diurnal -variation run was begun 

 on Septeml)er 18 but had to be abandoned after four 

 hours, owing to instrumental troubles. 



Potential-Gradient Recorder. --Altogether eleven 

 complete days' traces have been secured during the 

 period covered by this report. The principal cause of 

 loss of scalable trace was the necessity for frequent 

 operation of the main engine during the calm period re- 

 ferred to above. Minor losses of registration were as- 

 sociated with the loosening of the invar supporting rods 

 in the electrometer, a defective plug in the hourly zero 

 circuit, and poor illumination from the recording lamp. 



Conductivity Apparatus 8A.- -While the vessel was 

 in port at San Francisco, Mr. Gish, assisted by Mr. 



Parkinson, installed the recording apparatus. The skill- 

 ful design and beautiful mechanical workmanship of this 

 apparatus are illustrated by the fact that only very minor 

 difficulties were met with in its installation and records 

 were being obtained within a few days of the unpacking 

 of the boxes. Some adjustments were necessary when 

 operating under sea conditions, but these involved very 

 little loss of trace. Ten complete days' traces have 

 been obtained, five of positive and five of negative con- 

 ductivity. Owing to the possible effect of the fan motor 

 on the magnetic apparatus in the after dome, the fan is 

 shut off during the magnetic program. It is planned to 

 make tests of this effect as soon as possible, so that, if 

 it is negligible, no further interruptions of the conduc- 

 tivity traces will be caused. 



Ionic Content Apparatus l .--In general, this appa- 

 ratus has functioned normally. On September 16, how- 

 ever, a large leak, or fiber drift, wasobserved and after 

 exhaustive tests, it was found to be an effect of bound 

 charges on the amber insulators. In efforts to dissipate 

 these charges with radium, the trouble apparently was 

 accentuated and finally the insulators were left standing 

 for a day, after which no further trouble was encoun- 

 tered. 



