Aug. 1, 1870.] 



HARDWICKE'S SCIENCE-GOSSIP. 



179 



MARINE AQUARIA. 



THE recent article on the " Marine Aquarium " 

 by my friend Mr. C. Meltzer has, I hope, stimu- 

 lated the desire of many of your readers to possess 

 the means of carrying on the study of Marine 

 Zoology at home, and as the present season of sea- 

 side holidays would afford convenient opportunities 

 of establishing an aquarium, a few remarks on some 

 improvements which I have added to my own may, 

 perhaps, be acceptable. 



I had been in the habit of drawing off the water 

 to a certain extent daily, but in time it became 

 apparent, as my interest began to flag (as it some- 

 times will), that this was a somewhat fatiguing 

 process, and therefore one that was likely to be 

 forgotten for a day : thus greatly deteriorating the 

 condition of the water. In order, therefore, to 

 make the tidal arrangement as self-acting as pos- 

 sible, I added the following : — 



At the level of high-water mark I made a hole in 

 the slate back of my tank, through this I inserted 

 a glass tube (which may be made to fit completely 

 water-tight by placing over it a piece of India- 

 rubber tubing). This tube inside is bent down like 

 a siphon to the level of low water in the tank ; on 

 the outside it communicates with the jar receiving 

 the off- water. Now it will be seen that as soon as 

 the water reaches the level of the tube passing 

 through the back of the tank, it will flow over into 

 the outer tube communicating with the jar, and 

 this tube, by acting as a siphon, will draw off all 

 the water to the low-water level, which in my 

 aquarium is about two gallons. This is of course a 

 great saving of trouble, as with only once attending 

 to it, the water is made to rise to the highest level, 

 and, instead of getting heated in the aquarium by 

 remaining there, is drawn off into darkness again ; 

 and I think that with this arrangement it is almost 

 impossible that the water should get foul, except 

 by the grossest neglect. 



It occurred to me, however, that it would be 

 much better to draw the water off from the deeper 

 parts of the tank, instead of from the surface, as it 

 is in these dark parts and corners of an aquarium 

 that the sulphides and other evil gases are so prone 

 to form ; but how to draw off, by a self-acting 

 arrangement, the water from the bottom, and at the 

 same time make it stop at the required limit, for a 

 long time puzzled me. I, however, hit upon the 

 following plan : — A piece of gutta-percha or glass 

 tube is made to lead from the bottom of the tank, 

 and fixed firmly into a much larger tube, open 

 freely at the top to the air, into which the tube 

 rises. The projecting end of the running-off tube 

 s now fixed into the large open end of this tube, 

 0i t of which it draws the water, which of course 

 kefa)s rising to the general level through the bottom 



of the tube.* The advantages of this contrivance 

 are twofold : firstly, drawing off the vitiated bottom 

 water; and, secondly, preventing the escape of 

 small animals by the pipe. , 



In my aquarium arranged as above I have kept a 

 star-fish {Uraster rubens) in a perfectly healthy 

 state for twelve months, as also several limpets, 

 which I consider difficult to keep in health. I have 

 also noticed the spontaneous appearance of a beau- 

 tiful form of Medusa this summer, and I have had 

 tubularia develop finely. The aquarium is much 

 exposed to the weather, near an open window, and 

 has never been cooled in summer or warmed in 

 winter ; and during the residence of the above- 

 named star-fish in the tank, the water has been 

 above 80° Eahr., and at another time ice has been 

 all over its surface. 



I hope to give in a future paper some account 

 of ^the habits of the Echinoderms which I have 

 observed. Herbert Ingall. 



1, Champion Grove, Champion Hill. 



THE CURLEW. 



{Numenius arqicata.) 



A BOUT the end of July, or beginning of August, 

 -*-*- great numbers of shore birds come into our 

 harbours, and find their way from the mouths of the 

 rivers to a considerable distance inland. Grey 

 Plovers, Godwits, Knots, Whimbrel, Greenshanks, 

 Redshanks, Dunlin, and many other "waders," con- 

 tinue to arrive until the end of August, and the 

 shores and mud-flats which were so deserted during 

 the summer while the birds were away nesting, now 

 present a most animated appearance. Elocks of 

 various species, and of various sizes and colours, 

 from the tiuy brown Stint [Tringa viinuta) to the 

 great grey Heron, are scattered over the ground in 

 all directions ; now feeding busily as they follow the 

 receding tide, now flying with noisy call to some 

 more attractive spot. As we look down upon them 

 from the sea-wall, they appear to be all much of the 

 same colour, and are difficult to distinguish upon 

 the brown mud over which they are running. See 

 them in the air with upturned wings, and what a 

 different appearance they present. As the sun 

 strikes upon the pure white of the underparts borne 

 swiftly onwards by rapid wings, the eye is almost 

 dazzled at the bright contrast. Individuals are soon 

 lost to sight as they fly closer together, and the entire 

 flock, gradually lengthening out, sweep across the 

 harbour like a long wave, now light, now dark, as 

 the under or upper portions of the plumage are pre- 

 sented to view. Naturalists who visit the sea-side 

 at the period of migration to which we have alluded, 



* The water is run into the tank by a jet after the manner 

 described by Mr. Meltzer. 



