Sept. U, 1883 ] 



» KNOWLEDGE ♦ 



165 



This happens once in every sidereal lunar month, and 

 may happen more than once in each ordinary lunar month, 

 because the sidereal month is shorter than the lunation, and 

 if the moon is at O very soon after the beginning of a 

 lunation she will be again at O very soon after the end of 

 the lunation, — or pass O twice in that lunar month. But 

 it must happen once at least. 



We only notice the successive risings of the moon at nearly 

 the same hour, however, when she is conspicuous, — that 

 is, when she is full. We have to consider then at what 

 part of the year she will be full when at O (on the farther 

 hemisphere of Fig. 2), crossing the equator ascendingly, or 

 from south to north. This is a simple matter to determine. 

 As the moon is opposite the sun when full, it follows (since 

 her path is, nearly enough for our present inquiry the 

 same as the sun's), that if when full she is crossing 

 the equator ascendingly from south to north, he 

 must be near the opposite part of their common 

 path, or crossing the equator descendtngly from north 

 to south. This is where the sun is at the time of 

 the autumnal equinox. Consequently that full moon which 

 occurs nearest to the autumnal equinox, or say to September 

 23 or 2-1, is the full moon which of all the fuU moons in the 

 year rises on successive nights most nearly at the same 

 time. [I am quite aware of the inexactness of the wording 

 in this sentence. The moon is only full at a certain 

 moment. But I am speaking of phenomena as seen by 

 harvestmen and field labourers, to whom the moon is full 

 as long as her face looks round.] 



The full moon which thus rises nearly at the same time 

 on successive nights is called the harvest moon, because 

 her so rising is often convenient to harvest men. Often 

 however, (oftener indeed than not to the harvest men at 

 any given spot) the harvest moon occurs at such a time as 

 not to be of any special use in the way indicated. For 

 instance where I am writing (on September Gth) the harvest 

 is already gathered, — the moon being not as yet half full. 

 Harvest moon occurs on the IGth and will be of no special 

 advantage in this locality. Last full moon, wliich was not 

 harvest moon, was good enough in many places to serve all 

 the purposes of a harvest moon. 



To correspond to lower latitudes than ours, the point S 

 in Fig. 2 should be taken lower and the point N higher. 

 For higher latitudes the point S should be higher and the 

 point N lower. For the Arctic circle the point S should 

 be at M' the point N at m'. 



The same reasoning applies, with a change of seasons by 

 half a year, to the southern hemisphere. The same figure 

 would serve in fact if S and N be interchanged. The 

 harvest moon is manifestly as useful in the southern hemi- 

 sphere as in the northern, and within similar limitations. 

 All the lunar phenomena in the .southern hemisphere are 

 precisely the same for e\ ery latitude as for the correspond- 

 ing latitude in the northern hemisphere, — when we simply 

 writ(! southern for northern, and speak of spring, summer, 

 fall, and winter, instead of naming the months (which 

 correspond to diil'erent seasons in the two hemispheres). 



In the German Empire, exclusive of Hungary, last year 

 139,-152 railroad servants were examined as to their 

 capacity to distinguish colours. Of these, the liaUroad 

 lid-i'lfe says, 998, or 0"72 per cent., were found to be colour 

 blind. Of 11 .'ill-") I examined this year, only IG were 

 wholly and 273 partly colour-blind — 28 per cent, of the 

 whole number. 



its shortest, while the interval between successive sunsets is greater 

 than a mean solar day, and at its longest. 



THE CHEMISTRY OF COOKERY. 



XVIII. 

 Bv W. Mattieu Williams. 



I FIND that Sir Henry Thompson, in a lecture de- 

 livered at the Fisheries Exhibition, and now reprinted, 

 has invaded my subject, and has done this so well that I 

 shall retaliate by annexing his suggestion, which is that 

 fish should be roasted. He says that this mode of cooking 

 fisli should be general, since it is applicable to all varieties. 

 I fully agree with him, but go a little further in the same 

 direction by including, not only roasting in a Dutch or 

 American oven before the fire, but also in the side-ovens of 

 kitcheners and in gas-ovens, which, when used as I have 

 explained, are roasters, i.e., they cook by radiation, without 

 any of the drying anticipated by Sir Henry. 



The practical housewife will probably say this is not 

 new, seeing that people who know what is good have long 

 been in the habit of enjoying mackerel and haddocks 

 (especially Dublin Bay haddocks) stufied and baked, and 

 cod's heads similarly treated. The Jews do something of 

 the kind with halibut's head, which they prize as the 

 greatest of all piscine delicacies. The John Dory is 

 commonly stufi"ed and cooked in an oven by those who 

 understand his merits. 



The excellence of Sir Henry Thompson's idea consists 

 in its breadth as applicable to alljhh, on the basis of that 

 fundamental principle of scientific cookery on which I have 

 so continually and variously insisted, viz., the retention of 

 the natural juices of the viands. 



He recommends the placing of the fish entire, if of 

 moderate size, in a tin or plated copper dish adapted to the 

 form and size of the fish, but a little deeper than its thick- 

 ness, so as to retain all the juices, which by exposure to 

 the heat will flow out ; the surface to be lightly spread 

 with butter and a morsel or two added, and the dish placed 

 before the fire in a Dutch or American oven, or the special 

 apparatus made by Burton of Oxford street, which was 

 exhibited at the lecture. 



To this I may add, that if a closed oven be used. Rum- 

 ford's device of a false bottom, shown in Fig. 3, of Xo. 11 

 of this series, should be adopted, which may be easily done 

 by simply standing the above-described fish dish, with any 

 kind of support to raise it a little, in a larger tin tray or 

 baking dish, containing some water. The evaporation of 

 the water will prevent the drying up of the fish or of its 

 natural gra\y ; and if the oven ventilation is treated with 

 the contempt I have recommended, the fish, if thick, will 

 be better cooked and more juicy than in an open-faced 

 oven in front of the fire. 



This reminds me of a method of cooking fish which, in 

 the course of my pedestrian travels in Italy, I have seen 

 practised in the rudest of osterias, where my fellow guests 

 were carbonari (charcoal burners) waggoners, road-makuig 

 navvies, itc. Their staple " "ia^rro," or fast-day material, 

 is split and dried cod-fish imported from Korway, which in 

 appearance resembles the hides that are imported to the 

 Bermondsey tanneries. A piece is hacked out from one of 

 these, soaked for awhile in water, and carefully rolled in a 

 piece of paper saturated with olive oil. A hole is then 

 made in the white embers of the charcoal tire, the paper 

 parcel of fish inserted and carefully buried in ashes of 

 selected temperature. It comes out wonderfully well- 

 cooked considering the nature of the raw material. 

 Luxurious cookery en papiUote is conducted on the same 

 principle and especially applied to red mullets, the paper 

 being buttered and the sauce enveloped with the fish. In 

 all these cases the retention of the natural juices is the 

 primary object. 



