20 



HARDWICKE'S SCIENCE-GOSSIP. 



of research. To Mr. Goss belongs more credit than 

 to any one we know who has devoted himself specially 

 to fossil entomology. 



Cement for Fossils. — I have some very fragile 

 fossil remains of which I desire to make sections. 

 Will some reader kindly inform me if there be any 

 transparent cement with which I can saturate them, 

 fluid when hut, but perfectly hard when cold. Neither 

 gelatine nor plaster of Paris, &c, will do, since the 

 fossils must be ground down with water, and the 

 plaster is too opaque. — P. F. L. 



Siphonias. — There is a group of sponges known 

 as Siphonias. Will some one inform me if they are 

 confined to the Greensand, or if any members of the 

 group are found in the upper or lower chalk ? — 

 K. F. L. 



NOTES AND QUERIES. 



A Curious Calculation about Sparrows 

 and Sparrowhawks. — In Science-Gossip for 

 November, 1879, I see ^ r - Dealy has been "inter- 

 esting our readers with a curious calculation " about 

 sparrows and sparrowhawks. I was much interested 

 in his "curious calculation," as a curious example 

 of how easily some people can prove that to be truth 

 which they wish to be true. I will take for granted 

 as true the groundwork of his calculation, and en- 

 deavour to lessen the contrast he has drawn between 

 the sparrow and the sparrowhawk to the discredit 

 of the former. Indeed, at the outset, I will presume 

 the whole of his " curious calculations " to be as 

 correct as a naturalist's figures ought to be. What 

 then ? Is Mr. Dealy one of those men who think 

 that man and his wants are the only things in creation 

 worth a moment's thought or consideration ? One 

 pair of sparrowhawks in 20 square miles ; 3 sparrows 

 per day to each bird, makes 2190 per year ; 100 

 grains of wheat to each sparrow, makes 219,000 as 

 the number of grains of wheat which the sparrow 

 would consume, or rather which the sparrowhawks 

 would save in one year in 20 square miles. And as 

 there are 12,800 acres in 20 square miles, of which 

 we may suppose one-fifth to be under cultivation (I do 

 not know if this is exact, but it is sufficiently so for my 

 present purpose), leaves 2563 acres of cultivated land. 

 This divided into 219,000 gives the tremendous result 

 of 85 grains of wheat to be saved per acre of culti- 

 vated land by cultivating the acquaintance of sparrow- 

 hawks ! Does Mr. Dealy still begrudge the sparrow 

 his food ? But I find on looking at the preceding 

 part of Mr. Dealy's essay, that our calculation is much 

 too large. I have been presuming, or rather Mr. 

 Dealy has for me, that all the food of the sparrow- 

 hawk consists of sparrows, whereas the four birds he 

 himself opened, show that one-fourth only can be 

 reckoned as such. What then is the amount of damage 

 to be saved to the people of the British Isles by the 

 destruction of 185^ tons of sparrows yearly ? Just i6£ 

 loads. Value at retail price of 2d. per lb. = nearly^oo ; 

 or about I pipe of tobacco for each of the smoking 

 population in 15 years! "Farmers, agriculturists, 

 cannot you see ?" Now look at the other side of the 

 question. Would 1 bird in 40 eaten by the sparrow- 

 hawk, as taken from the farm-yard or game-preserve 

 be too much for his thieving propensities "' And would 



6d. each be too much at which to value the bird ? If 

 not, then over ,£8000 would be the price to be paid for 

 a saving of nearly .£400. At least one-half the food of 

 the sparrowhawk seems to be insect-eating birds. 

 So I shall be much within the mark if I say that one- 

 half the food consumed by the birds which form the 

 food of sparrowhawks is insects. And I think I 

 shall be very much within the mark if I say that each 

 bird consumes 4 times its own weight of food in one 

 year (without reckoning the insects taken to feed 

 their young, for which purpose sparrows, according 

 to some naturalists, catch a great number). We have 

 thus 13,304,250 birds, each consuming 8 oz. of food 

 (reckoning 2 oz. to a bird with Mr. Dealy), of which 

 40Z. will be insects, making 3,326,062 lbs. of insects. 

 Now 6 times its own weight of food would be a very 

 small amount for insects to destroy in one year. We 

 thus get 19,956,372 lbs. of food destroyed yearly by 

 insects which would be eaten by birds which form the 

 food of sparrowhawks. 19,956,372 lbs. at id. per 

 lb. (I have credited the sparrows with food]at 2d. per 

 lb.) gives over £ 83,000. This added to the £8000 

 worth of poultry and game, makes ,£91,000 at a low 

 estimate, as the price which must be paid to prevent 

 damage which at a high estimate cannot be more than 

 ,£400; and which damage, if done, is I believe 

 immensely compensated for by the number of insects 

 destroyed. Surely Mr. Dealy is joking when he 

 would have us protect the sparrowhawk on the score 

 of economy ! I think such a style of writing cannot 

 be too highly condemned, for it leads the ignorant 

 into error, while the more educated but unscientific 

 portion of the people are apt to class with it correct 

 and carefully prepared statistics.' — S. Woolley. 



Daucus Carota. — In December number, p. 27S, 

 right-hand column, line four, for the words "of the 

 side of" read " similar to." 



Work on Falconry. — What is the latest and the 

 best work on Falconry ? Can any ,of your readers 

 tell me where to get the hood, jesses, and complete 

 furniture of a falcon ? If not, can they tell me the 

 best manner to fasten the jesses on ? — P. M. K. 



Zoological Nomenclature. — Is there any work 

 giving the origin and the meaning of the specific and 

 generic nomenclature in zoology, but especially in 

 ornithology? If 1 not, I should think such a work 

 would be extremely interesting. — P. M. K. 



Frozen-over Fish-ponds. — The lines quoted by 

 Mr. Lloyd in his article last month on the above 

 subject are from the eighth canto of the first epistle 

 of Pope's "Essay on Man." — IVm. West, 15 Horton 

 Lane, Bradford. 



Unripened Figs. — "Penny Cyclopaedia" says, 

 " The fig-tree is very apt to throw off its fruit before it 

 ripens, and various methods have been suggested to 

 prevent this. In the Levant to insure a crop, a process 

 termed caprification is resorted to, which consists in 

 placing among the cultivated figs branches of the 

 wild figs, in which a kind of Cynips abounds. The 

 insect issuing from the wild fruit enters the others, 

 brushing about the pollen in the inside, and so 

 fertilising the fruit. Or those that drop prematurely 

 and are chiefly filled with male flowers are preserved 

 and introduced among the green growing figs with a 

 view to their pollen being carried by insects to the 

 flowers where it is wanted. Nothing is done in 

 England except ringing the shoots." — Bernard ITobson, 

 Sheffield. 



