500 



Qiieries and Answers. 



use at least 15 years. I have now made it evident that coulter tines have 

 been known in Ayrshire for 40 years, and the duck-footed ones for at least 

 15 : therefore, Mi-. Wilkie might have copied from those ; but my brother's 

 neither resembles them in appearance nor principle. I am, Sir, &c. — 

 Robert Finlayson. London, May 20. 1830. 



Art. VI. Queries and Ansxvers. 



Preventive for Glass cracking in Green-houses. — Sir, May I request you, 

 or one of your correspondents, to inform me of a preventive for the crack- 

 ing of glass in green-houses, from which I was a great sufferer last winter, 

 although I used but little fire, as I presumed it must proceed from the 

 unequal temperature of the external and internal air. I was, however, 

 somewhat staggered in my opinion by perceiving the breakage to be con- 

 fined to the upper (or roof) sashes, and also that it took place when there 

 was no artificial heat of any kind applied. — A Subscriber. Farleigh, near 

 Maidstone, Kent, June 24. 1830. 



We have little doubt that the breakage in question has been produced 

 by the freezing of the water which, in the case of glazing with the usual 

 broad lap, is retained in the interstices of those parts of the panes which 

 overlap each other. The lap need never be broader than a quarter of an 

 inch ; but where the panes are not above 5 in. wide, one eighth of an inch 

 is quite sufficient. Half an inch in roof sashes, unless they are placed at an 

 angle of not less than 45°, is almost certain of producing breakage, unless 

 the temperature within is sufficiently high to prevent the water retained 

 between the panes from freezing. — Cond. 



To destroy Rats, (p. 223.) — Your correspondent may hunt them with 

 dogs, but I should recommend him so to construct his banks, that they shall 

 be shallow and with a very gentle slope for about one yard or so above and 

 below the water mark, and then to Macadamise the same with stones full 

 6 in. thick. This will effectually prevent the rats doing harm to the puddle, 

 as it is always between wind and water where the mischief is done. — C. B. 

 York, May 5. 1830. 



Wire-ivorm (F/ later segetis) ; in an- 

 swer to O. C, Bucks. — The wire-worm 

 {fig. 93.) is the E'later segetis of mo- 

 dern entomologists : it belongs to the 

 order Coleoptera, and passes succes- 

 sively from the egg to the state of a 

 small worm (a), larger (b), chrysalis (c), 

 and perfect insect (d). — Cond. 



A Weevil which eats Fruit Trees in 

 the Nursery. — Sir, I some time ago 

 noticed a communication by the late Mr. 

 Hervey of Comber (Vol. V. p. 237.) respecting some insects that had de- 

 stroyed his fruit trees. For the last two years I have been very much 

 annoyed with what we consider the same beetle ; but as Mr. Hervey did not 

 state the mode in which they went to work, I have taken the liberty of send- 

 ing you a few in a small box by our friend, Mr. R. Rodger, who is a very 

 keen horticulturist. I find them commence their ravages in the months of 

 February and March. As soon as ever it gets dark, they leave the earth, 

 where they appear to burrow through the day, and ascend to the very top of 

 the apple and pear trees, and then turn their heads downwards, and eat off the 

 bark and buds in a screw-like manner, till they reach the foot of the tree. I 

 find them worst on the trees I cut over for dwarfs ; for, in the course of two 

 or three nights, they seldom leave a piece of bark or buds for 4 to 6 in. down. 



