November 2, 1899] 



NA TURE 



15 



out by the new process in the premises of the Szczepanik Com- 

 pany at Paris. The object of the photographic appliances of 

 Szczepanik is to take the artistic sketch, and, without any 

 modification of the same, to enlarge it to scale, to transfer it 

 Qn to ruled paper or point paper, and mark it with the thousands 

 and millions of dots arranged in the proper orders for the de- 

 velopment of the several parts of the pattern, in the weaves 

 qecessary for giving to each suitable precision of character when 

 woven. Prof. Beaumont considers that the apparatus of Szcze- 

 panik is capable of producing designs in which there is consider- 

 able diversity of woven detail, so that it is purely a question of 

 whether the designs thus obtained are legible for all practical 

 purposes. There must of course be limitations to its utility, as 

 there are to all automatic and mechanical appliances. Yet if it 

 can be employed in accelerating the process of designing large 

 patterns, it should have the serious attention of all who desire 

 the further development of the weaving industries. 



From a note in ihQ Journal of the Society of Arts, it appears 

 that there is reason to believe that in the near future mercury 

 will be one of the most valuable of the numerous metallic pro- 

 ducts of New South Wales. Native quicksilver was found so 

 fer back as 1841 in the Cudgegong River, an auriferous stream, 

 which flows through a portion of the western goldfields of the 

 Colony. Cinnabar had previously been found in the same 

 locality. Though efforts were made by the Rev. W. B. Clark 

 to stimulate systematic research for the metal and its ores, little 

 or nothing was done until later years, when cinnabar was found 

 at several places, the richest deposits being discovered near 

 Vulgilbar, in the Clarence River district, about four years ago. 

 The Government geologist has inspected the workings in this 

 locality, and has definitely ascertained the existence of three 

 parallel lodes, which improve as they go down. Machinery is 

 being erected, and a preliminary testing of about one thousand 

 tons of ore will be made. Should the results prove satisfactory 

 the New South Wales quicksilver trade will become revolution- 

 ised, as the poorest assays show the ore to be richer than those 

 of the American and Spanish mines. They will also encourage 

 the search for other cinnabar deposits, which, there is every 

 reason for believing, are more numerous and richer than gener- 

 ally assumed. The value of the discovery in connection with 

 the Colonial gold-mining industry can hardly be over-estimated. 

 It simply means that the work of gold production will become 

 enormously stimulated, thereby greatly increasing the already 

 large auriferous output of the Colony. 



The summary of the Weekly Wealher Reporl for the 

 September quarter of the thirty-four years, 1866 to 1899, 

 recently issued by the Meteorological Council, shows that 

 mean temperature for both wheat -producing and grazing 

 districts was 2° above the average. The only variations from 

 these values were in the east and west of Scotland, where the 

 excess was only 1°, and in the south and south-west of England, 

 where the excess amounted to 3". The general mean of 'the 

 rainfall for the quarter was 2 inches below the average in both 

 the above-mentioned districts ; the principal variations were in 

 the north and east of Scotland, where there was an excess of 

 I inch, and in the south-west of England, where the deficiency 

 amounted to 4 inches. Reckoning from January i, the differ- 

 ences from the averages are less marked ; in the east of 

 Scotland, the north-west of England and south of Ireland, 

 the excess amounts to about 2 inches, while in the east and 

 south of England the deficiency amounts to 27 and 3 '5 inches 

 respectively. 



Dr. E. S. Fatigati, of Madrid, has sent us a copy of an 

 interesting pamphlet in which he deals with the representations 

 of plants and animals, agricultural operations, and other natural 

 NO. 1566, VOL. 61] 



objects and activities found in very old Spanish tombs, in 

 cloisters of the eleventh and thirteenth centuries, corbels of 

 churches, and choir stalls of the fifteenth century. It appears 

 that the leaves, bunches qf grapes, and tendrils of the vine, 

 which were used as decorations during the classic period, are 

 also found in the oldest Spanish sculpture of the sixth and 

 seventh centuries. The animal world is well represented. The 

 swan, the gallinaceous birds, the dog, and the lion make up the 

 fauna of the little Asturian churches of the ninth century. In 

 the magnificent cloister of Silos (eleventh century) the in- 

 digenous species are found by the side of those of oriental and 

 northern origin. In the capitals of the cloister of Fawagona 

 (beginning of the thirteenth century) are reproduced in stone 

 two snakes devouring a frog, just as they may be seen 

 doing every day in the ponds of the country. In addition, re- 

 presentations are found of the fight of a hunter with a bear of 

 the Pyrenees, the capture of a hare by an eagle, and many 

 others of the same kind. The pictures of nature with its beings 

 and their struggle for life appear reflected in numerous monu- 

 ments. From these and many other facts given in the pamphlet 

 it seems that the Spanish sculptures of the Middle Ages have 

 not an exclusive symbolic character, and that in those days 

 Spain was not so separated from nature as many have supposed. 



Mr. John Brill, writing in the volume of Proceedings of the 

 London Mathematical Society just issued, discusses the complete 

 system of multilinear differential covariants of a single Pfaffian ex- 

 pression and of a set of such expressions. An account of the bi- 

 linear covariant of a Pfaffian expression is given by Forsyth ; this 

 covariant involves the first set of Pfaffians belonging to the 

 given expression, from which latter it is derived by a differential 

 operation. A repetition of this method upon the covariant 

 itself merely produces an expression which vanishes identically. 

 Mr. Brill shows how, by making use alternately of algebraic 

 and differential methods of derivation, a series of covariants 

 of the given expression can be produced which involve the 

 various orders of derived functions associated with the ex- 

 pression. It is to be noted that the places at which differential 

 operations occur are those which mark the passing from one 

 group of cases into the next in the case of a set of equations ob- 

 tained by equating the Pfaffian expressions severally to zero. 

 Furthermore, the more general derived functions introduced by 

 Mr. Brill play a similar part in regard to these latter coyariants 

 to that which the derived functions of a single expression play in 

 reference to its covariants. One of the main difficulties of the 

 subject is the extraordinary complication of the notation. 



An important paper on the development of the carapace of 

 the Chelonia is contributed by Dr. A. Goette to ^jie last 

 number (vol. Ixvi., part 3) of the Zeilschrift fiir Wissenschafl- 

 liche Zoologie, in the course of which the disputed question as 

 to the relationship of the leathery turtles (Athecata) to the 

 carapaced chelonians (Testudinata) is discussed. If the views 

 put forward by Dr. Goette are correct, they will profoundly 

 modify the generally accepted views as to the relations 

 of the Athecata and Testudinata— more especially the late 

 Dr. Baur's theory as to the former being a specialised group 

 with a degenerate type of carapace. 



In the August number of the Transactions of the Connecticut 

 Academy Mr. W. G. Vanhame records some recent experiment 

 in regard to the fertilisation and development of the Planarians. 

 From the ease with which these creatures can be kept in 

 captivity and the number of eggs laid, observations on the 

 development of the group would appear easy, but difficulties 

 have been met with by previous observers, in consequence of 

 which there are discrepancies and uncertainties in regard to 



