April 19, 19 17] 



NATURE 



Dj 



for frfijsical' investigations formed a large p>art of the 

 equipment of observatories in which the earlier work 

 in astrophysics was carried on. such as those of 

 Lock\-er and Hugg-ins, and Dr. King points out that 

 there is a constantly increasing demand for this close 

 co-operation between the laboratory and the observa- 

 tory. Though much work of great value has been 

 done in university laboratories, greater continuit}- in 

 the prosecution of extensive pieces of research is 

 possible in a laboraton,- which is specially equipped, 

 and provided with a staff having full time to. devote 

 to these problems. Typical examples of the experi- 

 mental work carried on at Mount Wilson are described 

 and illustrated; the photographs showing the effect 

 of the magnetic field on the sun-spot spectrum are 

 particularly striking. 



Parallax of a Planetary Nebula. — In view of the 

 doubtful value of most of the parallaxes previouslv 

 deduced for nebulae, a result recently obtained by 

 Mr. A. van Maanen with the 6o-in. reflector at 

 Mount Wilson is of considerable interest and import- 

 •ance (Proc. Nat. Acad. Sci. Washington, vol. iii., 

 p. 133). The nebula in question is N.G.C. 7662, 

 having a sharp stellar nucleus which gave measurable 

 images with exposures of twenty-five minutes. The 

 absolute p>arallax is given as 0023', which would 

 place the nebula at a distance of about 140 light-years. 

 As the angular diameter of this nebula is 26*, its 

 linear diameter would thus be of the order of nine- 

 teen times that of the orbit of Neptune. 



THE RECENT COLD WEATHER. 



AFTER a more than usually severe winter, the 

 spring has opened with exceptional cold over 

 the whole of Great Britain, and the wintrj- conditions 

 have also embraced a large part of western Europe. 



Dr. Mill, the director of the Rainfall Organisation, in 

 a letter to the Times of April 11, meniFons that "the 

 first ten days of .April have been colder this year than 

 in any other," according to the Camden Square record 

 of temperature, which has been kept for sixty years. 

 Frost is said to have occurred on ever\- night but 

 two. In the Camden Town records for 1888 frost 

 occurred everj- night but one, although the mean 

 temperature for the period was slightly higher than 

 in the present month. The Greenwich records for 

 the past sevent}-fiye years show that prior to the 

 present year the greatest cold for the first ten days of 

 April occurred in 1888, when the highest night tem- 

 perature for the period was 32-1° on April i. At South 

 Kensington, the recording station of the Meteoro- 

 k)gical Office, frost occurred in the open on thirteen 

 nights during the first fortnight of April this year. 



The cold has been even more severe over the 

 northern portions of the kingdom ; and in the official 

 reports from the health resorts, Southport is shown 

 to have had a minimum shade temperature of 13° on 

 April 3. 



In the winter six months, from October to March 

 inclusive, there was frost on seventy-three nights at 

 Greenwich. During the last seventy-fiv^ years frost 

 has only occurred more frequently in the six winter 

 months six times, whilst the winter which has just 

 closed has had a greater number of frosts than any 

 winter since that of 1890-91, when there were seventy- 

 six frosts. The highest number is eightj- frosts, in 

 the winter of 1887-88. . _ _ 



The frequencv of snow in London is dealt with in 

 the Times of April 11, and records by a meteorolc^st 

 at Wandsworth Common for the last quarter of a 

 century are referred to. Snow is said to have fallen 

 on as many as thirty days this year prior to April iJ, 

 and since that date snow has fallen on four more 

 days to April 17. so that snow has fallen on thirty- 

 NO. 2477, VOL. 99] 



four days since the commencement of January. This 

 is three times the average for the first four months 

 of the year, and is eleven more than in any correspond- 

 ing period since 1892.. The average number of days 

 with snow in an entire year at Wandsworth Common 

 for the past twenty-five years is thirteen. Mr. Mossman, 

 in a communication made to the Royal Meteorological 

 Society- some years ago, showed that the average 

 number of davs with snow was fifteen in' the course of 

 the year, deduced from the observation of 100 years, 

 and twelve of these snowy days occurred in the first 

 four months of the year. 



Snow has fallen in larger quantities during the last 

 few months over the northern portion of the kingdom 

 than in the south, although the occurrence of the 

 snow may not have been more frequent. 



In 1908 railway traffic was much hampered in the 

 south of England by a heavy fall of snow on April 25, 

 and ordinary- trafiic by road was completely stopped 

 for a time. 



Rainfall for the past winter was less than in many 

 recent winters, and the total for the six months in 

 London was 144 in., which is about no per cent, of 

 the average. January and February- were dry, little 

 more than one-half of the average rain falling in the 

 latter month. Sunshine has been deficient for months 

 past over England, and in London there has been an 

 unusual number of overcast and sunless days. 



Chas. Harding. 



MEMORIAL TO SIR WILLIAM AND LADY 



HVGGIXS. 



Address by Sir J. J. Thomson, O.M., P.R.S. 



WE gave on -\pril 5 (p. 109) an account of the 

 unveiling of a memorial to Sir William and 

 Lady Huggins in St. Paul's Cathedral. The address 

 delivered by Sir Joseph Thomson on that occasion 

 has since reached us, and we are glad to be able to 

 print it below. 



I have been asked, as president of the Royal Societ}-, 

 to commit this memorial of Sir William and Lady Hug- 

 gins to the care of the Dean and Chapter of St. Paul's, 

 and also to say a few words as to the inception of 

 the memorial. Shortly after the death of Sir William 

 Huggins some of his friends were anxious to set 

 on foot a proposal to obtain a memorial of him ; this 

 came to the knowledge of Lady Huggins, and she 

 expressed the wish that she might be allowed to 

 defrav all the expenses, so that no one except herself 

 should be put to any expense in the matter. Before 

 anv arrangements had been arrived at Lady liuggins 

 died, and it was found that in her will she had left 

 a sum of money to provide for a memorial to Sir 

 William. It seemed to those responsible for carrying 

 out her wishes that in view of the long and active 

 part she had taken in her husband's work, and that 

 some of the most important papers were published in 

 their joint names, no memorial to Sir William would 

 be satisfactory unless it testified in some way to the 

 part Lady Huggins had played in his work ; to eflfect 

 this a small medallion of Lady Huggins had been 

 added as a pendant to the one of Sir William. 



There can be no question as to the claim of Sir 

 William Huggins, the founder of astrophysics, as 

 he has been called, to such a memorial, nor an\- 

 doubt as to where it could most appropriately be 

 placed. For no man of equal scientific eminence was 

 ever more ck>sely connected with this city. He wa? 

 bom in London, he was educated entirely m London, 

 he was in business in London, and when he retired 

 from business to devote himself to astronomy he built 

 his obser\'atory in London ; and in sjMte of the fact 



