8o 



NATURE 



\May : 4 , 18S3 



friend, Sir Charles Macarthy, then Colonial Secretary, my 

 zoological and botanical tastes being well known to the latter. 



The conversation turning on plants, the Abbe described a 

 wonderful tree which he had seen, on the leaves of which were 

 impressed thousands of likenes-es of Buddha. Nothing was 

 said about " Thibetan characteis," nor did he lead us to suppose 

 it grew larger than an ordinary cinnamon-tree (not bush), as it 

 grows wild. His description was so detailed that, in spite of the 

 florid language of a French traveller, I at once recognised a 

 plant which grew not uncommonly in our gardens, the leaves of 

 which were often placed in the finger-glasses after repasts, as on 

 being crushed, they imparted a delicious fragrance to the hands. 

 Looking up and catching the eye of our hostess, in which lurked 

 an amused smile, I made the motions of dipping hands in a 

 finger-glass. She instantly caught my meaning, whispered her 

 instructions to the servant behind her chair, and each finger-glass 

 — which useful adjunct to a meal was shortly after placed on the 

 table — contained a leaf or two of what we used to call by a 

 variety of names, such as the " profile laurel," or " figure 

 laurel," or "face laurel." 



The face of the Abbe was a picture to behold. " But here it 

 is ! " he exclaimed. " Where did this coaie from ? " We then 

 explained that it grew not a dozen yards fro n where he sat, to 

 his great astonishment, and I fancied not a little chagrin, that 

 his wonderful plant should be so well known and common. 



The plant is, I believe a laurel. It ha; flashed across me that 

 it may be a citron, but the plant is s) well known in Ceylon, that 

 if your contributor, Mr. W. T. Thi-elton Dyer, wishes to 

 ascertain its name, he has but to write a line to the Director of 

 the Botanical Gardens, Peradenia, who will at once recognise it. 



The leaves are broad and pointed, shaped in fact somewhat 

 like the cinnamon. Down each side of the midrib, extending 

 along the veinlets (I write from memory, remember) are patches 

 of pale greenish-yellow, much lighter than the ground-colour of 

 the leaf. These take innumerable fantastic, face-like shapes — 

 always profile — and with the aid of a pin, or point of a dessert- 

 fork, we, in 



" Those merry days, 

 The merry days, when we were young," 



used to put in an eye, and amu-e ourselves in trying to find like- 

 nesses of our friends and acquaintances. It was a source of 

 much fun among the young people. 



The events of that morning were, from a variety of circum- 

 stances, deeply impressed on my memory, and I am positive that 

 then nothing was said about "Thibetan characters" on the 

 leaves or on the bark, nor of the great size of the tree, and the 

 Abbe distinctly recognised the leaves as identical with those he 

 had seen. You w ill perceive he calls it the "Tree of the Ten 

 Tnou-and Images" (the italics are mine). This name would well 

 apply to the " profile laurel," fir no two faces are ever alike, 

 but does not include characters. 



Whether the size of the tree and the " Tnibetan characters " 

 grew (in the Abbe's brain ?) after he left Ceyl in, I do not know. 

 The "real arti;le" seems to have vanished. A bungling attempt 

 to deceive by etching in lilac leaves could easily be detected, but 

 " travellers see strange things " ! E. L, Layard 



Brit. Consulate, Noumea, Ne.v Caledmia, March 5 



Sheet-lightning 



The correspondence on this subject (Nature, vol. xxviii. pp. 

 4 and 54) can scarcely be said to contribute anything in support of 

 the statement that sheet-lightning and the so-called summer or 

 heat-lightning, are nothing else than the reflection of, or the 

 illumination produced by, distant electrical discharges. The 

 table given in the review (.Nature, vol. xxvii. p. 576) is not a 

 record of instances of sheet-lightning, but only the number of 

 hours, sorted according to the twenty-four hours of the day, in 

 which sheet-lightning or heat-lightning was observed at Oxford 

 during the twenty-four years ending 1876. In constructing the 

 t ible, all those hours were excluded in which thunder was heard, 

 and also the hour immediately preceding and following the hour 

 of occurrence of thunder. Only those hours, therefore, were 

 included during which auy thunder that may have accompanied 

 the lightning was at some distance from Oxford. 



It follows simply as a matter of statistics that, if all cases of 

 sheet lightning are nothing el-e but the illumination produced by 

 distant electrical discharges, the curve of thunder and the curve 

 of sheet-lightning and heat-lightning should be approximately 

 parallel to each other after darkness has fairly set in. The 



Oxford observations show that such is njt the case. To make 

 this quite clear wengive the results for August only : — 



Thunder. Lightning. 



8-9 p.m S o 



9-1° .. 3 5 



io-ii „ 4 6 



11-mid. 3 14 



Mid.-I a.trj 2 14 



1-2 ,, 2 12 



2-3 >> I 4 



3-4 .. o 3 



These two sets of figures from 8 p.m. to 4 a.m. furnish two- 

 curves quite distinct from each other ; and the difference is not 

 to be explained by the degree of facility for recording the obser- 

 vations afforded by each separate hour. It may be added that a 

 similar result is obtained from electrical manifestations in other 

 parts of the globe during the summer months. It is from these 

 facts that it was concluded that no inconsiderable number of the 

 cases of sheet-lightning and heat-lightning are not illuminations 

 produced by distant electrical discharges, but, as suggested by 

 Loomi<, are rather to be considered as due to the escape of the 

 electricity of the cbuds in flashes so feeble that they produce no 

 audible sound, and they occur when the air being very moist 

 offers just sufficient resistance to the electricity to develop a 

 feeble spark. The Reviewer 



Solar Halo 

 The following, taken from vol. i. Philosophical Transactions, 

 p. 219, may interest your readers, as the phenomenon appears 

 to coincide almost exactly with the one recorded in Nature, 

 vol. xxviii. p. 30. I omit the illustration, though it corresponds 

 almost exactly with the one in Nature, except that there were 

 mock suns. 



"An account of four suns, which very lately appear' d in France, 

 publi-hed in the French Journal des Scavans of May 10, 1666 : — 

 " ' The 9th of April of this present year, about half an hour 

 past nine, there appear'd three circles in the sky. One 

 of them was very great, a little interrupted and white every- 

 where, without Ihe mixture of any other colour. It passed 

 through the midst of the sun's disk, ant! was parallel to the 

 horizon. Its diameter was above a hundred degrees, and its 

 center not far from the zenith. 



" ' The second was much less, and defective in some places, 

 having the colours of a rainbow, especially in that part which 

 was within the great circle. It had the true sun for its center. 



" ' The third was less than the first, but greater than the second, 

 it was not entire, but only an arch or portion of a circle whose 

 center was far distant from that of the sun, and whose circumfer- 

 ence did by its middle join to that of the least circle, intersect- 

 ing the greatest circle by its two extreams. In this circle were 

 discerned also the colours of a rainbo.v, but they were not so 

 strong as those of the second. 



" ' At the place where the circumference of this third circle did 

 close with that of the second, there was a great brightness of 

 rainbow colours mixt together. And at the two extremities 

 where this second circle intersected the first, appear'd two 

 parhelias or mock suns,' &c, &c." 



In a note to this account it is stated that " Five suns appear'd 

 the 29 March, A., 1629, at Kome between 2 or 3 of the clock in 

 the afternoon." In the illustration given we find two circles 

 similar to those given in Nature. It seems that two of these 

 suns " which were in the intersection of two circles, appear'd in 

 that of a circle, which passed through the sun's diske, with 

 another, that was concentrick to the sun." 



The phenomenon of last week was minus the parhelia ; can 

 any reason be given for this? Thos. Ward 



Northwic -, May 15 



In reply to Mr. Mott's query (p. 30) I beg to say that I 

 measured the halo with a sextant as carefully as possible, and 

 made the semidiameter 25°. [Another halo occurring on the 

 13th measured 23° 20'.] 



With regard to the mock moons, they were perfectly equi- 

 distant from the horizon all the time I ob erved them, and I 

 regret that 1 did not notice that Mr. Mott had seen them other- 

 wise. I read his letter rather hurriedly and thought the expres- 

 sion " out of place" referred to their position above the moon, 

 and not to a want of parallelism with the horizon. Sm. 



Temple Observatory, Rugby, May 17 



