68 



♦ KNOWLEDGE ♦ 



[Aug. 3, 1883. 



modern science, is nothing more nor less than the systematic 

 and orderly application of common sense and definite mea- 

 surement to practical questions. In this case it may be 

 applied simply by frying a weighed quantity of any par- 

 ticular kind of fish — say sprats — in a weighed quantity of 

 fat used as a bath ; then weighing the fat that remains and 

 subtracting the latter weight from the first, to determine 

 the quantity consumed. If the frying be properly per- 

 formed, and this quantity compared with that which is 

 consumed by the method of merely greasing the pan- 

 bottum, the bath frying will be proved to be the more 

 economical, as well as the more efficient method. 



The reason of this is simply that much or all of the fat is 

 liui'nt and wasted when only a thin film is spread on the 

 bottom of the pan, while no such waste occurs when the 

 bath of fat is properly used. The temperature at which the 

 dissociation of fat commences is below that required for 

 delicately browning the surface of the fish itself, or of the 

 tiour or breadcrumbs, and therefore no fat is burnt away 

 from the bath, as it is by the overheated portions of a 

 merely greased frying-pan, and as regards the quantity ad- 

 hering to the fish itself, this may be reduced to a minimum 

 by withdrawing it from the bath when the whole is uni- 

 formly at the maximum cooking temperature, and allowing 

 the fluid fat to drain off at once. When cooked on the 

 greased plate, one side is necessarily cooling, and the fat 

 settling down into the fish, while the other is being heated 

 from below. 



PRETTY PROOFS OF THE EARTH'S 

 ROTUNDITY. 



CHIEFLY FOR THE SEASIDE. 



By Richard A. Proctor. 



ALTHOUGH I suppose none of the readers of Know- 

 ledge entertain any manner of doubt as to the 

 rotundity of the earth, it is not unlikely I think that 

 some will find the illustrations or proofs of that rotundity 

 which I propose to describe in this and a few following 

 papers, somewhat novel. They have occurred to me during 

 my residence at the seaside in former years and recently, 

 and during my travels over prairie levels in North 

 America, and so far as I know have not as yet found a 

 place in text^tooks of astronomy. Just now when many 

 readers of Knowledge are at the seaside these methods 

 or some of them will be found especially interesting, since 

 the sea-surface constantly illustrates terrestrial rotundity. 



Let me premise that as commonly presented in works on 

 astronomy the proof of rotundity afibrded by the appear- 

 ance of ships as they pass over the horizon limit and 

 beyond, is apt to introduce a serious difiiculty, though 

 sound enough in itself. We are shown in a picture entirely 

 out of proportion, a roimd hill of water over the top of 

 which a line of sight is carried from an observer as at 

 A, Fig. 1, a departing ship being shown in several posi- 

 tions as at 1, 2, 3, 4, fully seen at 1 and 2, hull down 



The bath-frying, of course, demands separate supplies 

 of fat — one for fish, another for cutlets and other similar 

 kinds of meat, a third for such goody-goodies as apple- 

 fritters — a most wholesome and delicious dish, too rarely 

 seen on English tables. I suspect that the prevalence of 

 the greased frying-pan is the reason of its rarity. Cooked 

 by this barbaric device, apples are scarcely eatable, but 

 when thin slices are immersed in a bath of melted fat 

 at a temperature of about 300° F., the water of their juice 

 is suddenly boiled, and as this water is contained in a mul- 

 titude of little bladder-like cells, they all burst, and the 

 whole structure is pufted out to a most delicate lightness, 

 far more suitable for following solid meats than soddened 

 fruit enveloped in heavy indigestible pudding - paste. 

 Another advantage is that with proper apparatus (wire 

 basket, stew-pan, and store of special fat) the fritters can 

 be prepared and cooked in about one-tenth of the time 

 demanded for the preparation and cookery of an apple 

 pudding or pie. A few seconds of immersion in the fat- 

 bath is sufficient. 



But the fat that has been used several times requires 

 purification. This is especially the case with that devoted 

 to fish-frying. The purification of fat is an important 

 and interesting process that I will endeavour to treat as 

 simply as may be in my next. 



*^* There is no Editorial Gossip this week for the reason 

 that the Editor's medical adviser recommends cessation for 

 the present from all work not absolutely necessary. 



at 3, and showing upper part of mast only at 4 to the 

 spectator at A. In such pictures the depression of the 

 line of sight Aa touching the convexity of the water, 

 or the angle aAt which it makes with the horizontal line 

 At, is so considerable as to be obvious. Now the student 

 is thus taught two things, — one true the other untrue. 

 He learns correctly enough how and why a ship disappears 

 beyond the convexity of the sea ; but he is also taught 

 what is not correct, viz. that the sea horizon dips obser- 

 vably below the true horizon, and that the depression of 

 the sea horizon becomes obviously greater as the observer's 

 height above the sea-level increases. When the learner is 

 next at the sea-side and notes that there is no such visible 

 depression, nay that when he is a good deal above the sea- 

 level the sea horizon appears (by an optical illusion, 

 indeed, but still very strikingly) higher than when he 

 stood on the seashore, he is apt to think he has been 

 wrongly taught on the other point also. 



It was in this way indeed that the small but lively 

 sect of flat-earth men were deceived by the man who under 

 the pseudonym Parallax has borne — for reasons best known 

 to himself — three surnames of more familiar sound, and to 

 this day the peculiarity in question is the one Ijy which his 

 followers are deluded. It cropped up in the notorious 

 Bedford Level experiment by which the wager respecting 

 the rotundity of the earth was decided ; and I fancy that 

 to this day, on the strength of this misleading peculiarity 

 the loser of that foolish wager considers that he was most 

 hardly dealt with. The experiment actually made on that 



