226 



KNOWLEDGE 



[October 2, 1899. 



lobsters are so prolific in individuals, they are content with 

 an exceedingly modest number of genera and species. In 

 this respect they differ from the crayfishes and the craw- j 

 fishes which have many of both. Of the crawfishes several 

 are very handsomely coloured, of large size, extensively 

 distributed, and very numerous. One well-known species, 

 Jasu^ /fl/rt?i(/(i (Lamarck), is said to afford abundant food 

 for the poorer classes at the Cape of Good Hope, besides 

 keeping a factory at work for tinning and exporting it. 

 Including the antenna it is generally about three feet long 

 and it is sometimes longer. 



Hermit crabs do not look as if they could ever be inviting 

 diet, yet an aberrant member of the group, the Bayiis | 

 latro or Cocoanut crab, is a celebrated dainty. | 



Of the common rrab it is needless to sing the praises. 

 Rather is it to be lamented that no enterprising person will 

 try to acclimatise amongst us, in favoured situations such 

 as Cornwall or the Isle of Wight, the river-crab of the 

 Continent, Potmnon fluviatilis, said to be a tempting 

 delicacy. The not less admired land crabs of the West 

 Indies might not take kindly to our wilful temperature, 

 and must be content to be eaten in their native haunts. 

 The large spider-crab. Main squiniuki, sometimes very 

 plentiful in the South of England, is eaten appa,rently, as 

 some jokes are laughed at, only out of compassion. The 

 poor creature is perhaps maligned by a misnomer,^ for 

 when Mr. Thomas Bell, the carcinologist, asked a little 

 girl, who had some ready cooked for sale, whether they 

 ate those crabs, she replied, " They ben't crabs, sir, them's 

 spiders." Concerning another member of this family, 

 Tilesius, in 1812, relates that it occurred very plentifully 

 in Kaintchatka in a bay deriving its name from the 

 abundance of the crabs, and that " the sailors of the Niva 

 eagerly sought after the species, finding it to be very 

 delicious as food." But on this point, as on one or two 

 others, mankind speak not all with one mouth. In the 

 United States of America the blue crab, CnlUnectes hastatus, 

 is the common edible crab, and it is most esteemed just 

 after exuviation, in what is known as the soft-shelled con- 

 dition. It has recently received the alternative name of 

 siipidus, the tasty one. Lt(pa jiehifjica, prized among us as 

 a specimen for its striking form and beautiful colouring, is 

 the common edible crab of Sydney in Australia, 



Without further exemplification, then, it is evident that 

 the generous globe in every zone, from sea or river or 

 land, offers man some delectable Crustacea to embellish 

 his meals. Some of them may not be suited for our food. 

 Some of us may not have gastric arrangements suited for 

 feeding on them. But in being generally wholesome and 

 generally palatable, few large groups either of animals or 

 vegetables surpass the Crustacea, and, in any case, they eat 

 up things that we do not want, and are eaten up by things 

 that we do, thus by a happy transmutation of species 

 supplying blubber to the starving Eskimo, sealskin to the 

 luxurious European, and all sorts of fish to all sorts of 

 people all over the world. 



1898. 

 July 19 

 „ 20 

 ., 22 

 .. 23 

 ,. 24 

 „ 25 



Sep. 



28 



5 



7 



8 



9 



13 



14 



15 



17 



18 



, 10 



11 



12 



13 



13 



14 



15 



16 



17 



IS 



(invisible) 

 (maximum) 



(invisible) 



(maximum) 



(cloudy) 

 (cloudy) 



Mag, 



8-75 

 8-25 

 8-25 

 S-55 

 8 90 

 1005 



8-41 

 831 

 814 

 8-18 

 813 

 8-13 

 8-23 

 8 95 

 9-67 



8-35 



(invisible) 



189S, Mag 



Nov, 19 



1899, 



Jan, 6 (7,30 p.m., invisible) 

 6 (8.00 p,iu.,TcTy faint) 

 6 (8,40 „ less than 1000 

 „ 7 ... S'65 



„ 8 8-35 



,, 10 (about maximum) 



Bad weather till 

 „ 14 ,,, 835 



„ 16 ... 88 



Mar, 13 .,, 87 



Maximum three or four days 

 earlier, 

 (invisible) 



Julv 



(later maximum) 825 

 8 35 

 (cloudv) 



.., ' 9-35 



9-50 

 9-95 



These are the means of 

 night. 



S . S CYG 



40 



1 



2 

 3 



4 



5 



6 



7 



8 



9 



10 ..'. 



11 

 12 (barely visible) 



(cloudy) 



(cloudy) 

 (maximum ) 



8-3() 

 8-30 



8-40 

 835 



8-20 

 8-52 

 8-75 

 9-60 

 10-20 



several observations the same 



Nl . 



-44" 



b' 



75 



-4.3' 



Maqs 

 a . 9 7 

 h-S 4 

 e ,9 .^ 

 n- - .') .9 

 If 10 n 



-oi" 



My observations of U. Orionis at its last appearance 

 are as follows ; — 



[The Editors do not hold themselves responsible for the opinions or 



statements of correspondents.] 



» 



S. S. CYGNI. 

 To the Editors of Knowledge. 

 Sir, — As Dr. Hartwig, at the last European Conference, 

 called attention to the variable star S. S. Cygni, which 

 seems to be designated as R' in " The Companion to the 

 Observatory," the following ephemerides may be of 

 interest to your readers. Its period is irregular. 



