HARDWICKE'S SCIENCE -GOSSIP. 



139 



the water; directly afterwards it darted in, and 

 then returned to the bank with a small fish in its 

 mouth, which it at once made a meal of. In oppo- 

 sition to the above, a eat which 1 have has a very 

 great aversion to wetting either its mouth or paws, 

 especially the former. I have often been amused 

 when watching it eat bread and milk, for instead of 

 taking a piece of bread out of the plate with its 

 mouth, it generally jerks it out on to the floor with 

 one or two hasty snatches of the paw, and then eats 

 it; it a'so much dislikes being out in the rain, 

 always getting under the nearest cover. — James H. 

 Allchin, Dover. 



Turntables. — I have been trying to improve my 

 turntable, a plain one I bought of Mr. Baker, 

 optician, of Holborn. I found the concentric guide 

 circles on the brass were not easily seen, so I tried 

 paper summed on, and marked with ink circles; 

 this did for a time, but used to come off. I also 

 wanted some secure fastening for the slide, and 

 found that Mathew's plan did not allow of finishing 

 off any slide badly centred. I accomplished my 

 wishes thus : I had a circle about one inch in 

 diameter sunk in the face of the table, so that a 

 round piece of thick paper or thin card, cut to fit it, 

 could just lie in it : this can be marked in any 

 colour or way wanted (it is but to have several 

 different ones), and cannot easily be moved by the 

 glass slip. I tried several plans of fixing the slide, 

 but they were too complicated to please me, and 

 would have been expensive; at last I hit upon the 

 following, which 1 find answers. I cut a piece of 

 wood thin enough to go under the springs, so as to 

 •fit between the screws, and present a standing edge 

 to the glass slip; another thin piece serves as a 

 wedge, and is so shaped that when a slide one inch 

 wide rests against it, the edge is parallel to a line 

 drawn through the screws, and it is properly centred. 

 An eccentric button, with a large screw for its axis, 

 enables the slide to be so firmly pressed against the 

 wedge that no force likely to be used will move the 

 slide. Of course brass would be better than wood, 

 but I find wood do well for a and to. The buttou 

 must be so placed that it will allow the slide to be 

 wedged towards the button for about one-eighth of 

 an inch. This will give ample play for a badly- 

 centred slide. A wider wedge will be wanted for this, 

 and if more play is wanted, the pieces a and to must be 

 removed, and the old plan adopted. Of course the 

 slide can be moved towards either end as required. 

 The screw fastening the button should be large, as 

 it keeps the button firmer. Mr. Baker, of Holborn, 

 made me a button to my pattern, and could, I doubt 

 not, alter any turn-table, or I would give him a 

 pattern to do it by. I would suggest that a hollow 

 should be cut out of the solid wood of the turntable 

 to receive the pieces, and this could be closed by a 

 slide. My turntable had no rest for the hand, and 

 I have used a glass letter-weight, but a solid wooden 

 rest would be better. Perhaps I may be allowed 

 next mouth to describe a simple apparatus to help 

 true centring in mounting, which 1 think an im- 

 provement on the block I recommended some months 

 ago. — W. Locock. 



Nests of Mice.— A correspondent in the April 

 number of Science-Gossip gives us an account of 

 the nest of the short-tailed field-mouse. I am glad 

 of the opportunity of adding a word or two re- 

 garding the home of our common mouse. From the 

 disagreeable odour pervading it, I discovered that a 

 colony of mice had found out that good things were 

 to be obtained from a large cupboard in my house. 



Here I left all the food for my poultry. A bag of 

 wheat indicated that these "brownies" were enjoying 

 themselves immensely. Having purchased some 

 penny traps, 1 was successful in catching them all, 

 or frightening some away. But on removing an 

 inverted box, about one foot square, I was astonished 

 to see a heap of what appeared to me to be very 

 thin fibres, lying on the shelf. Such was the fact. 

 A small basket was very neatly stripped round the 

 lower part of its broader pieces of osier, and these 

 had been torn into shreds varying from f inch to 

 linch in length. All these little pieces (about a 

 handful) had been made into a nest, and I was 

 rather surprised to see that it was constructed just 

 like a bird's nest, with the opening above. It was 

 very loosely put together, but still compact enough 

 to hold two little corpses, the parents having unfor- 

 tunately met their fate by the enticing taste of 

 roasted cheese. — A. H. 



Cleaning Aquaria.— I have seen various modes 

 of cleaning aquaria suggested, but know of none so 

 efficient as the following. If your globe or tank is 

 to go through a thorough cleaning, and has a coating 

 of green cr a growth of confervoid on the glass or 

 slate, take a lump of salt and rub over the sides, 

 and it will take off the growth of confervoid in- 

 stantly, and will not, injure or scratch the glass. 

 The salt to be slightly wetted with water on its 

 surface when rubbing the glass. — J. J. R. Sclater, 

 Teign mouth, Devon. 



To Clean Corals. — Have ready two large 

 vessels that will take and cover the largest specimen 

 of coral with water when filled, that you intend to 

 clean. Keep one full of clean water, aud have 

 boiling water enough to fill the other. Now have 

 ready a bottle of spirits of salts, muriatic acid. To 

 every three gallons of boiling water use one pound 

 of the acid. Your specimens of coral must be close 

 to hand, so as to dip them in the boiling water and 

 acid. The dirt will come off the coral instantly. 

 Pass the specimens to a second person to wash 

 them in the clean water, and then place them in the 

 sun to dry. If very dirty, let them remain longer in 

 the acid and boiling water. Dead shells can be made 

 to look very nice served in the same way, and will 

 retain a polish if not washed in the clean water. If 

 the acid water should be too dirty, make some clean 

 with a little more acid and boiling water. Dip in 

 quickly, then place them out to dry. When dry, you 

 will find a nice gloss on them, and you would think 

 you were handling live shells instead of dead ones. 

 — A. J. B. Sclater, Teignmouth, Devon. 



White Varieties.— On reading "W.'s" re- 

 marks in your last number of Science-Gossip on 

 white and other varieties of flowers, I thought 1 

 might supplement his observations by some notes 

 of my own. I have seen Cardamine pratensis, var. 

 alba, as near London as Wimbledon Common. 

 Campanula rotund if olia, alba, has appeared occa- 

 sionally on Clapham Common, and Pediadaris 

 sylvatica, very pale, but not quite white, is often 

 seen on Wandsworth Common. I have not yet 

 seen a wild white Colckicum, but it may interest, 

 " W." to know that in Brewer's "Flora of Surrey," 

 page 238, it is said to have grown on the Wray 

 Park estate, and " the flowers vary in colour from 

 white to purple." The cream-white, as well as the 

 coloured varieties of Symphytum officinale, may be 

 found in several places along the course of the 

 Hampshire Avon. Erica tetralix, quite white, I 

 found last autumn in little clumps (associated with 



