44 



OCEAN ATMOSPHERIC -ELECTRIC RESULTS 



Penetrating Radiation Apparatus 1. - -Except for 

 some erratic behavior at the beginning of the diurnal- 

 variation run on September 18, this instrument has 

 worked normally. Comparison observations with this 

 apparatus and the Kolhorster instruments 5503 and 5658 

 mentioned below have been made daily. 



Kolhorster Penetrating Radiation Apparatuses 5503 

 and 5658. --Apparatus 5658 was received at San Francis- 

 co on the arrival of Mr. Gish. During the stay of the 

 vessel in San Francisco, Mr. Gish, assisted by Messrs. 

 Parkinson, Jones, and Seaton, made a series of obser- 

 vations with the two instruments, both in air and under 

 water, at Crystal Lake. Both instruments appeared to 

 be somewhat erratic in behavior and the cause for the 

 discrepancies between them is obscure. Apparatus 5658 

 is being returned to Washington with Mr. Gish. 



Nuclei Counters 2 and 5. --Instrument 2, received 

 at San Francisco was tried out soon after leaving port 

 but was found to leak badly. An examination by Mr. Gish 

 showed some bad mechanical defects and the instrument 

 is being returned from Honolulu. Counter 5 apparently 



is working normally; nevertheless, it is advisable that 

 a second instrument be available on board for compari- 

 sons. 



Radioactive Content Apparatus. --Mr. Gish has spent 

 considerable time installing and adjusting the new poten- 

 tial-multiplier device received at San Francisco. He 

 also made several alterations in the assembly and re- 

 wired the apparatus. Trouble is still experienced in 

 maintaining a steady high potential on the central cylin- 

 der. A trial observation was made on September 22 and 

 it is hoped that frequent determinations will be possible 

 from now on. 



Batteries. --In view of the good performance of the 

 Burgess "B" batteries and some advantages they pos- 

 sess over batteries composed of silver chloride cells, 

 the latter type has been eliminated from use with the 

 various instruments. The present stock of Burgess bat- 

 teries is ample for some considerable time, but, if fur- 

 ther supplies have to be shipped to the Carnegie , it might 

 be well to specify the "knob type" terminal rather than 

 the "spring type" previously supplied. 



HONOLULU, HAWAH TO PAGO PAGO, SAMOA, OCTOBER 2 TO NOVEMBER 18, 1929 



General. --The eye observations of ionic content, 

 penetrating radiation, and nuclei count have been made 

 whenever possible --practically daily. Four complete 

 diurnal-variation runs have been made. Special obser- 

 vations of penetrating radiation, using radium as an 

 ionizing constant, have been made, as described below. 

 Considerable computational work has been done on a 

 preliminary reduction of potential-gradient values to 

 show that diurnal variation proceeds on universal time. 



Potential-Gradient Recorder. --This instrument has 

 worked moderately well. Thirty-eight complete days' 

 traces have been obtained. On October 3 the recording 

 paper became loose from the lower roller and therefore 

 did not rotate. Heavy rains on October 11 and 12 caused 

 some loss of trace--a considerable quantity of water 

 accumulated in the collector-insulator tube, presumably 

 having splashed up inside from the top of the instrument 

 box. From this time, at intervals, until the end of Oc- 

 tober, frequent periods of earthing occurred for which 

 the reason is still uncertain. The collector system was 

 disassembled and carefully reassembled several times 

 but the earthing recurred after varying intervals. The 

 Indications were that there was a definite metallic con- 

 nection to ground rather than poor insulation, as a spark 

 could be obtained when the collector hood was connected 

 to a battery. On October 23 the electromagnet, which 

 operates the hourly zero, burned out and, presumably at 

 the same time, the amber surface of the central insula- 

 tor in the collector tube was badly scarred. It is be- 

 lieved that a defect in the engine room power circuit oc- 

 curred during the time the hourly zero was in operation. 

 The coil was removed and it was intended to replace it 

 by the one on recorder 4947. The holders for these 

 coils, however, are not interchangeable on the two in- 

 struments and, in disconnecting the good coil, the wire 

 from the center broke off too short to be repaired with- 

 out rewinding. It has been necessary, therefore, to 

 make manual zeros, two or three each day, and, as the 

 zeros have been very constant, it is thought that this 

 will suffice until a new coil is received and fitted. 



Conductivity Apparatus 8A. --The performance of 

 this recorder has been most gratifying. Scalable values 



have been obtained for every hour, except one, of every 

 day since leaving Honolulu. Thus forty-seven complete 

 days' traces are available--twenty-three for positive 

 and twenty-four for negative conductivity. Csdibrations 

 of both signs have been made frequently and the mean 

 curves show very little variation with lapse of time. On 

 October 29 a thermometer was fitted to the electrome- 

 ter house, with bulb inside and scale outside, and, for 

 calibrations subsequent to this date, temperature read- 

 ings have been made and recorded. On October 18 one- 

 hour runs were made, on both signs, with an ionium col- 

 lector in the air-flow tube. The ratio of positive to 

 negative conductivities derived from these tests was 

 1.17. From the mean values of positive and negative 

 conductivities obtained for observations made between 

 October 2 and 31 (using only undisturljed days, eleven of 

 each sign) which were 1.30 x 10-4 and 1.08 x 10-4, re- 

 spectively, a ratio of 1.20 was derived. On October 24 

 the duration of the hourly zero was increased from four 

 to six minutes. On October 25 one of the recording 

 drums began to stick, in the same manner as was en- 

 countered on several days during September. The drum 

 was taken apart and greased, but the stoppages recurred 

 on October 29 and 31. The driving spring therefore was 

 removed and the drum has worked quite well without it. 

 On November 10 the same thing happened to the other 

 drum; so the spring was removed from it also. The fol- 

 lowing interesting features of the conductivity traces 

 might be mentioned: (a) The sudden change in type of 

 trace at 16 h 45 m hours on October 7, for which no cor- 

 responding change in meteorological or other factors to 

 which it might be related, could be found; (b) the change 

 from land to sea conditions soon after leaving Honolulu 

 on October 3; (c) the sudden decrease in values during 

 rain. It was noticed that the values of ionic mobility 

 derived from the conductivity records and from eye ob- 

 servations of ionic content are somewhat high and rather 

 more variable than those previously obtained. This 

 question invites some investigation which can no doubt 

 be carried through more effectively at Washington than 

 on board ship. 



Ionic Content Apparatus I. --N0 difficulties have 



