March lo, 1881] 



NA TURE 



435 



English ; and Portuguese authority seems to liave been lessened, 

 through that Power being interested in acquiring possessions 

 elsewhere, and the island was for a while deserted, though still 

 used by the captains and crews of ships as a South Atlantic 

 post-office. It was customary to place letters under huge 

 boulders of stone, marked in a conspicuous manner, so that 

 the crews of ships returning from India might obtain news 

 from home. An interesting record of this period is still to be 

 seen on a rude block of lava measuring nearly five feet high and 

 two feet six inches \a ide, W'hich has been preserved by being 

 subsequently built into a large mass of uasonry in the James- 

 town burial-ground." 



In the Galapagos Islands there is a bay named Post-Office 

 Bay, which seems to indicate an analogous nautical exchange 

 station. 



I sulijoin Victor Hugo's description, and shall be much 

 obliged to any of your readers who can refer me to any ac- 

 coimt of the earlier voyagers whence this scene was derived. 



S. P. Oliver 



2, Eastern Villas, Anglesey, Gosport, Febraary 2S 



P.S. — If any one can give me a reference, also, where I can 

 find an account of the wreck of the Grosvcnor on the south-east 

 coast of Africa in 1782, I shall be extremely obliged. 



" Lcs Travaillairs de la Mer, edition illustree (1866). Livre 

 cinquieme, ix. 



— Renseignement utile aux personnes qui attendent, ou 

 craignent, des lettres d'outre-mer" (p. 91). 



" Ne disiez-vous pas, Capitaine Gertrais que la Tamatilipas ne 

 relachera point ? 



— Non. II va droit an Chili. 



— En ce cas il ne pourra pas donner de ses nouvelles en route. 



— Pardon, Capitaine Clubin. D'abord il peut remettre des 

 depeches a tons les bailments qu'il rencontre faisant voile pour 

 Europe. 



— C'est juste. 



— Ensuite il a la boite aux leltirs de la met: 



— Qu'appelez-vous la boite aux lettres de la mer ? 

 . — Vous ne connaissez pas 9a, Capitaine Clubin ? 



— Non. 



— Quand on passe le detroit de Magellan. 



— Eh bien ? 



— Partout de la neige, toujours gros temps, de vilains mauvais 

 vents, une mer de quatre sous. 



— Apres ? 



— Quand vous avez double le cap Monmouth. 



— Bien. Ensuite ? 



— Ensuite vous doublez le cap Valentin. 



— Et ensuite ? 



— Ensnite vous doublez le cap Isidore.' 



— Et puis ? 



— Vous doublez la pointe Anna.' 



— Bon. Mais qu'est ce que vouz appelez la boite aux lettres 

 de la mer ? 



— Nous y sommes. Montagues a droite, montagnes a gauche. 

 Des pingouins partout, des petrels-tempetes. Un endroit 

 terrible. Ah ! mille saintes mille singes ! Quel bataclan, et 

 comme 9a tape ! La bourrasque n'a pas besoin qu'on aille a 

 son secours. C'est la qu'on surveille la lisse de hourdi ! C'est 

 la qu'on diminue la toile ! C'est la qu'on te vous remplace la 

 grande voile par le foe, et le foe par le tourmentin ! Coups de 

 vent sur coups de vent. Et puis quelque-fois quatre, cinq, six 

 jours de cape seche. .Souvent d'un jeu de voiles tout neuf il 

 vous reste de la charpie. Quelle danse ! des rafales a vous faire 

 sauter un trois-mats comme une puce. J'ai vu sur un brick 

 anglais, le ' True Bluc;' un petit mousse occupe a la ' giiboojii' 

 emporte a tons les cinq cent mille millions de tonnerres de Dieu 

 et la ^ gibhoom ' avec. On va en Pair comme des papillons, quoi ! 

 J'ai eu le contre-maitre de la Revenue, une jolie goclette, arrache 

 de dessus le fcrc-crosstree, et tue roide. J'ai eu ma lisse cassee, 

 et mon serre-goutliere en capilotade. On sort de la avec toutes 

 ses voiles mangees. Des friegates de cinquante font eau comme 

 des paniers. Et la mauvaise diablesse de cute ! Rien de plus 

 bourru. Des rochers dechiquetes comme par enfantillage. On 

 approche du Port-Famine. La c'est pire que pire. Les plus 

 nides lames que j'ai vues de ma vie. Des parages d'enfer. Tout 

 a coup on aper9oit ces deux mots ecrits en rouge : Post Office. 



— Que voulez-vous dire, Capitaine Gertrais? 



— Je vous dire, Capitaine Clubin, que toute de suite ajres 



qu'on a double la pointe Anna on voit sur un caillou de cent 

 pieds de haut un grand baton. C'est un poteau qui a une 

 barrique au cou. Cette barrique, c'est la boite au lettres. II a 

 fallu que les anglais ecrivent dessus : Post Office. De quoi se 

 melent ils? C'est la poste de 1' ocean ; elle n'appartient pas i 

 cet honorable gentleman, le roi d'Angleterre. Cette boite aux 

 lettres e^t commune. Elle appartient a tous les pavilions. Post 

 Office, est-ce assez chinois ? (^'a vous fait Peffetd'une tasse de the 

 que le diable vous offrirait tout a coup. Voici maintenant comment 

 se fait le service. Tout batiment qui passe expedie au poteau un 

 canot avec ses depeches. Le navire qui vient de I'Atlantique 

 envoie ses lettres pour I'Europe, et le navire qui vient du Pacitique 

 envoie ses lettres pour I'Ameriqne. L'officier commandant votre 

 canot met dans le baril votre paquet et y prend le paquet qu'il 

 y trouve. Vous vous chargez de ces lettres-la ; le navire qui 

 viendra apres vous se cbargera des vOtres. Comme on navigue 

 en sens contraire, le continent d'ou vous venez, c'est celui ou je 

 vais. Je porte vos lettres, vous portez les miennes. Le baril 

 est bitte au poteau avec une chaine. Et il pleut ! Et il neige ! 

 Et il gicle ! Une fichue mer ! Les satanicles volent de tous 

 cotes. Le TamauUpas ira par l.a. Le baril a un bon couvercle 

 a charniere, mais pas de serrure ni de cadenas. Vous voyez 

 qu'on peut ecrire i ses amis. Les lettres parvienneut. 

 — C'est tres-drole, murmura Clubin rcveur." 



Explosive Gas in a Lake 



A friend, on whom 1 can rely, informs me that during the 

 late frost, Loch Ken in Kirkcudbrightshire was frozen over, 

 affording pastime to curlers and skaters. Here and there, how- 

 ever, small spots of the surface, near to the shore, resisted the 

 frost lonjer, and when they did freeze the ice was very thin. 

 These pot-holes were dangerous to skaters, the largest being 

 about size enough to admit an ordinary curling stone. Gas was 

 emitted from them, and when the ice for the first time was formed 

 over them one person got his face severely burned by boring a 

 small hole in the thin ice and setting fire to the gas thus liberated, 

 with a match. After a while the gas seemed to lose its power 

 of combustion and the experiment could be repeated with 

 impunity, a feeble flame only being evoked, when the hole was 

 first drilled. ]■ Shaw 



Dumfriesshire, March 4 



Colours of British Butterflies 

 The sober colouring of the under-wings of many of our 

 butterflies is universally accepted as being "protective." Let 

 the gorgeous "peacock," for in-tance, but close his wings, audit 

 takesa s'oarpeye to see him. Why then should he and so many 

 other kinds flaunt their most brilliant hues in the brightest sun- 

 shine, and often be rendered even more conspicuous by perching 

 on a yellow flower? One would think that this was the exact 

 way to attract birds, especially as the colours are not likely to 

 be "warning " ones, for if so, why the sober hues of the under 

 sides of the wings? The colours can hardly be " warnings " to 

 particular kinds of birds and "protective" against the attacks 

 of others. The explanation may be that the facilities for recog- 

 nition, and thus for the continuation of the species, are so much 

 greater in bright light, as to render it advantageous on the whole 

 to run the chance of easier capture in the brighter parts of the 

 day : or it may be that relatively few birds feed at the times that 

 butterflies choose to display their beauties. 



In watching butterflies it appears clear that they are, so to 

 speak, shortsighted, for it is the commonest thing pssible'.i 

 see tvvo entirely different sorts circle round each other for some 

 time as if they had to decide whether they are of the same kind 

 or not. In doing this it will be observed that they fly, as it 

 were, over and over each other, so that for quite half the time 

 the gambols are going on, the dark side of the "protected" 

 kinds is shown to the insect below, t ' ere steps in a provision 

 which seems admirably adapted for enabling recognition to take 

 place. It will be found that though the wings of protectively 

 coloured butterflies appear very dark at a casual glance, yet that 

 if they are held up to the light, in many cases there are bright 

 spots or colourings or semi transparent spaces, that, by enabling 

 the sun to shine through, make even the dark wings very con- 

 spicuous. The bright spots on the "peacock" are a case m 

 point I have not an opportunitv of actually handling a com- 

 plete collection of our British butterflies just now. but in thirty of 

 our commonest sorts I find fiftacr. that have distinctly protectively 



