April so, 1885] 



NATURE 



601 



Quinquefoliate Strawberry 



It may interest botanical readers to know that we have here a 

 variety of strawberry many petioles of which hear five leaflets. 

 This kind of leaf is also transmitted to its offspring when propa- 

 gated by runners, and I think it may be possible to raise from 

 seed progeny the whole of whose petioles will bear five leaflets. 

 It is an excellent variety in every respect ; the fruit is sym- 

 metrical, and of rich flavour. When we consider that Duchesne's 

 strawberry, Fragaria monofihylla (described by Mr. Dyer in 

 Nature, vol. xxix. p. 215), was unifoliate, and that ordinary 

 strawberries are trifoliate, this variety certainly is unique, and 

 suggests still further possibilities of development in the genus 

 Fragaria. J. Loyell 



Driffield, April 16 



SOME OF THE METEOROLOGICAL RESULTS 

 OF THE TOTAL SOLAR ECLIPSE OF MA Y 6, 

 1883 ' 



IN the expedition sent by the United States Govern- 

 ment to Caroline Island (9° 59' 45" S. lat. and 

 150 14' 24" W. long.) to observe the total eclipse of 

 May 6, 1883, provision was made for taking a series of 

 meteorological observations on the occasion. The ob- 

 servations, which were of an elaborate description, are 

 fully detailed and summarised by Mr. Upton in the 

 Report, and they present results of exceptional interest. 



During the eclipse the velocity of the wind remained 

 practically constant, and, so far as the readings of the 

 radiation thermometers showed, the heat received by the 

 earth was almost nil. The temperature of the air, which, 

 previous to the eclipse, had been 84°'5, fell to SU'4, or 

 o c- i lower than it had been at 7 a.m., and o c- 6 lower than 

 it was at 9 p.m. The amount of the temperature depres- 

 sion due to the withdrawal of the sun's heat was 3°'9 ; 

 and, corresponding with this lowering of the temperature, 

 the relative humidity increased 5 per cent, during the 

 eclipse. 



The main interest of the observations, however, centres 

 in the influence of the eclipse on the diurnal barometric 

 curve. The diurnal march of the atmospheric pressure 

 in these regions may well be classed among the most 

 regularly recurring phenomena of terrestrial physics. 

 From hourly observations made from April 25 to May 5 

 the mean at 10 a.m. was 29-957 inches, and at 2 p.m. 

 29-844 inches, the barometer thus falling in these four 

 hours 0-113 inch. Between these hours, on May 6, the 

 eclipse occurred, the total phase of the eclipse being from 

 11-32 to 11-37 a.m. On that day the barometric curve 

 presented a form wholly different from what is daily ob- 

 served in these regions. From 10-30 to 11-25 am - tne 

 barometer fell with a greater rapidity than the normal 

 rate of fall, being at 11.20 am. 0016 inch lower 

 than the normal at that hour. Immediately there- 

 after a rapid and abnormal rise set in, the usual 

 fall being arrested and replaced by an actual rise, so that 

 while pressure at 1 1.20 a.m. was 29.927 inches, at 

 11.50 a.m. it was 29-940 inches. At 12.10 p.m. it was 

 0-019 'nch above the normal for that hour. Since the 

 barometer was o'oi6 inch lower than the normal at 

 11.20 a.m., and 0-019 inch higher at 12.10 p.m., it 

 follows that the disturbance from the normal values 

 during these fifty minutes occasioned by the eclipse 

 amounted to 0-035 inch, being equal to nearly a third of 

 the whole diurnal oscillation from the morning maximum 

 to the afternoon minimum. 



The time and manner of this abnormality is of special 

 significance, inasmuch as it indicates a more rapid fall 

 than the average during the first partial phase, when the 

 sun's heat began to be cut off, and a rise above the 

 average wholly exceptional after the close of the total 

 phase, the maximum rise being delayed thirty-three 



' Report of observations made on the expedition to Caroline Island to 

 observe the total solar eclipse of May 6, 1883, by Winslow Upton. (Wash- 

 incton, 1884.) 



minutes after the period of totality. An eclipse differs 

 essentially from all other influences affecting the atmo- 

 sphere, in that it cuts off the sun's heat from a restricted 

 section of the earth's atmosphere extending from the 

 surface to the extreme limits of the atmosphere, while 

 from the air surrounding the shaded region the sun's 

 heat is not cut off. Now, the observations showed that 

 the first effect of the cutting off of the sun's rays and 

 consequent reduction of the temperature, which no 

 doubt extended through the whole height of the atmo- 

 sphere, was to lower the pressure below the normal. 

 This diminished tension was simply the direct result of 

 the lowering of the temperature of the air over the region 

 where the barometric observations were made. 



Following this diminution of the pressure, an inflow 

 of air towards the retreating path of the shadow set in, 

 and pressure quickly rose above the normal of the hour, 

 and as the sun's rays now heated the air with this excess 

 thus temporarily accumulated over Caroline Island, pres- 

 sure rose still further, till at thirty-three minutes after the 

 close of the total phase it was 0019 inch above the 

 normal. Thereafter pressure fell with a corresponding 

 rapidity during the next twenty minutes, at the close of 

 which time it stood at the normal. The whole phases of 

 the disturbance in the diurnal march of the pressure 

 caused by the eclipse occupied two hours ending with 

 12.30 p.m. It is from their bearings on the theory of the 

 diurnal oscillations of the barometer that Mr. Upton's 

 observations must be regarded as of the highest 

 importance (see " Encyclopaedia Britannica," Meteorology, 

 pp. 122 and 123). 



Pointed attention is given in the report to the observa- 

 tions of the wind, which showed that, though the island is 

 situated in the region usually included in the south-east 

 trades, yet the direction of the wind was almost always 

 noted as east or north-east, and was at no time observed 

 to be from any other quarter than between north and 

 east. Not a single observation during the time the 

 expedition was on the island gave a direction south of 

 east. The Challenger in this part of its cruise, during 

 September, 1S75, noted the same directions of the wind, 

 and during the cruise to southward the north-east trades 

 were not left till lat 1 3' S. was reached. 



During the voyage from Callao, the Hartford sailed 

 day after day in the region of the south-east trades, upon 

 almost the same parallel of latitude, and with but few 

 changes in the position of the sails, no steam being used. 

 Since the conditions were so constant during the twenty- 

 two days in which the vessel sailed in lat. 11° 5' S. from 

 long. 79° to 137° W., a tabulation of the hourly speed of 

 the vessel day by day has been made from the ship's log. 

 The mean values show a distinct increase in the evening, 

 and a corresponding decrease in the morning, the maxi- 

 mum, 6 - 8 miles per hour, occurring at 10 p.m., and the 

 minimum, 5-9 miles, at 10 a.m. With reference to the re- 

 sult, Mr. Upton remarks that, " It seems fair to attribute 

 this to a diurnal variation in the wind's velocity. There is 

 quite an unexpected regularity in the progression when 

 we consider the approximate nature of the method. If 

 not attributable to diurnal change in the wind itself, it 

 yet indicates a diurnal change in the effect of the wind 

 upon the sails, and is therefore of interest." 



SIR WILLIAM THOMSON ON MOLECULAR 



DYNAMICS 1 



III. 



BEFORE proceeding with new parts of this subject, I 

 wish to say a few words about " fiddling while Rome 

 is burning." Sir William Thomson writes to me that the 

 expression was used while discussing some mathematical 

 triviality, and he wishes to be relieved of the imputation 



1 Continued from p. 510. 



