214 



NATURE 



{June 28, 1888 



in their experiments on the specific inductive capacity of gases. 

 — Mr. W. Lant Carpenter exhibited a new form of lantern, 

 recently constructed by Mr. Hughes, of Dalston. The mahogany 

 body is hexagonal, and each of the three front sides is provided 

 with condensers and projecting arrangements. The back side 

 opens to give access to the radiant, which in this case is a 

 Brockie-Pell arc lamp, but if necessary a lime-light can be 

 readily substituted. The lamp is fixed to the base-board, and the 

 body can be rotated through 6o° on either side of the central 

 position, thus allowing any of the three nozzles to be directed 

 towards the screen. The three sets of condensers are placed so 

 that their axes intersect at a point about which the radiant is 

 placed. The centre nozzle is fitted as a lantern microscope, 

 with alum cell and various sets of condensing lenses and ob- 

 jective*, and a space in front of the main condensers is provided 

 for polarizing apparatus. The focussing arrangement consists 

 of a skew rack and pinion and a fine screw adjustment, and the 

 whole microscope can be easily removed and a table polariscope 

 substituted. The right-hand nozzle is arranged for the projec- 

 tion of ordinary lantern-slides, and the left-hand one is provided 

 with an adjustable slit for spectrum work. A small table sliding 

 on rails serves to carry the prisms, and the same rails support 

 projecting lenses. Prof. S. P. Thompson congratulated Mr. 

 Lant Carpenter on his selection of the Brockie-Pell lamp as the 

 radiant, for, in addition to its being a focussing-lamp, it is 

 unique in the fact that it works satisfactorily on either constant 

 current or constant potential circuits. — Note on some additions 

 to the Kew magnetometer, by Prof. Thorpe, F.R. S., and 

 Prof. Riicker, F.R. S. In their magnetic survey of Great 

 Britain and Ireland the authors have experienced considerable 

 difficulty in making the necessary adjustments of the small 

 transit-mirror used for determining the geographical N. point 

 from observations on the sun. To make the required adjust- 

 ments it is necessary to obtain an image of the cross-wires 

 reflected from the mirror ; and owing to the large amount of 

 extraneous light, and the insufficient illumination of the cross- 

 wire, the image is difficult to see. To exclude extraneous light, 

 a tube is placed between the transit-mirror and the telescope, 

 and a small screen placed behind the mirror. The cross-wires 

 are illuminated by light reflected from a small platinum mirror 

 introduced between the eye-piece and the cross-wires, which are 

 viewed through a hole in its centre. The mirror is placed at 

 45 to the axis, and reflects a considerable quantity of light on 

 the cross-wires when directed towards a bright part of the sky. 

 In some cases it is advisable to take observaiions of the sun 

 without first adjusting the transit-mirror, and afterwards correct 

 the error introduced thereby. To do this a finely-divided scale 

 is placed in the plane of the cross-wires, and from the position 

 of the image, as indicated on the scale, the correction can be 

 made. Observations taken with the mirror in adjustment and 

 others taken when out of adjustment, and subsequently cor- 

 rected, give very concordant results. The Rev. Father Perry 

 said the improvements described were of great importance, for 

 difficulties similar to those experienced by the authors had 

 caused him to abandon the Kew magnetometer for field work, 

 and to use a theodolite instead. 



Linnean Society, June 21.— Mr. F. Crisp in the chair. — 

 Mr. F. W. Oliver exhibited the aquatic and terrestrial forms of 

 Trapella sinensis, of which he gave a detailed account, illustrated 

 by diagrams.— Dr. R. C. A. Prior exhibited a branch of the 

 so-called "Cornish elm," and described its peculiar mode of 

 growth, which suggested its recognition as a distinct species. 

 In the opinion of botanists present, however, it was regarded as 

 merely a well-marked variety of the common elm. — On behalf of 

 Mr. R. Newstead, of the Grosvenor Museum, Chester, photo- 

 graphs and drawings of the little grebe, Podiceps minor, were 

 exhibited to illustrate a peculiarity observed in the mechanism 

 of the leg-bones. — Mr. A. W. Bennett exhibited under the micro- 

 scope, and made remarks upon, filaments of Spharoplea annu- 

 lina_ (from Kew), containing fertilized oospores. — Mr. Thomas 

 Christy exhibited specimens of natural and manufactured Kola 

 nuts, and explained how the latter might always be detected. — 

 The following papers were then read : — Dr. P. H. Carpenter, 

 on the Comatulce of the Mergui Archipelago. — Prof. P. Martin 

 Duncan and W. P. Sladen on the Echinoidca of the Mergui 

 Archipelag).— Mr. W. P. Sladen, on the Asteroidea of the 

 Mergui Archipelago.— Mr. W. Bolus, on South African 

 Orchideiz. — Mr. R. A. Rolfe, a morphological and systematic 

 revision of Apostasies. 



Geological Society, June 7.— Dr. W. T. Blanford, F.R.S. 

 President, in the chair. — The following communications were 

 read : — A letter from H. M. Secretary of State for India, accom- 

 panying some specimens of rubies in the matrix from Burma. — 

 On the Sudbury copper deposits (Canada), by J. H. Collins. — 

 Notes on some of the auriferous tracts of Mysore Province, 

 Southern India, by George Attwood. — On the Durham salt- 

 district, by E. Wilson. In this paper the author described the 

 new salt- field in the North of England, occupying the low -lying 

 country bordering the estuary of the Tees, and situated partly in 

 Yorkshire and partly in Durham. The history of the rise and pro- 

 gress of the salt-industry in South Durham was given, since the 

 first discovery of salt by Messrs. Bolckow, Vaughan, and Co., at 

 Middlesborough, in the year 1859. The stratigraphical position 

 of the saliferous rocks of the Durham salt-district was considered 

 in some detail. The diverse views which have been previously 

 expressed on this head were referred to, and reasons given for 

 concluding that all the beds of rock-salt which have been hitherto 

 proved in this field, and the red rocks with which they are 

 associated, belong to the upper portion of the Trias, viz. to the 

 Upper Keuper series (Waterstones subdivision). The probable 

 area of this salt-field, the limits of the distribution, and varying 

 depths of the chief bed of rock-salt were indicated, and the 

 extent of its supplies pointed out. In conclusion, the author 

 called attention to the waste, as well as to certain other disad- 

 vantages resulting from the process of winning the salt now in 

 operation. — On the occurrence of Cahispharce, Williamson, in 

 the Carboniferous Limestone of Gloucestershire, by E. Wethered. 

 — Second note on the movement of scree-material, by C. 

 Davison; communicated by Prof. T. G. Bonney, F.R. S. 



Anthropological Institute, May 29.— Francis Galton, 

 F.R.S., President, in the chair. — A paper by Mr. G. H. 

 Kinahan was read, on rubbings from ancient inscribed stone 

 monuments in Ireland. — Dr. Stewart gave an account of the 

 inhabitants of Paraguay. 



June 12. — The Rev. H. G. Tomkins read a paper on Mr. 

 Flinders Petrie's collection of ethnographic types from the monu- 

 ments of Egypt. The author classified the collection under the 

 four heads of Westerns, Southerns, Asiatics, and Egyptians ; 

 and examined, in order, the races mentioned under each of these 

 heads. Among the Westerns are the Tahennu, or fair people, 

 who, as Egyptian mercenary troops, founded, by a praetorian 

 revolt, the famous twenty-second dynasty, to which Shishak, the 

 invader of Palestine, belonged. The Lebu, or Libyans, fall 

 under this head ; and the author identifies with them the light- 

 complexioned, fair-haired, and blue-eyed brickmakers of the 

 celebrated tomb of Rekhmara. The want of the long side-locks 

 is not surprising, since they were slaves employed in the lowest 

 drudgery. The Shardina furnished highly-trained soldiers to 

 the Egyptian army of Rameses II. They wore helmets with 

 two horns, crested with a disk, and seem to have been Sar- 

 dinians. Under the head of Southerns we have very various 

 and interesting types. It is curious to find, in the paintings, 

 blacks with red hair ; but it seems probable that the colour was 

 produced by the use of dye. Mr. Tomkins gave a full descrip- 

 tion of the race of Pun, and dwelt particularly upon the terraced 

 mountains covered with incense-trees that caused so much 

 astonishment to the officers of Queen Hatasu. He also gave 

 a probable explanation of the origin of the remarkable features 

 of Amenhotep IV., the celebrated Khu-en-aten, whose mother, 

 Queen Tua, was distinguished for her beauty. 



Mathematical Society, June 14. — Sir J. Cockle, F.R.S., 

 President, in the chair. — The Vice- Chancellor of Cambridge 

 University (Dr. C. Taylor), read a paper on the determination 

 of the circular points at infinity. -Prof. M. J. M. Hill followed with 

 a paper on the c- and /-discriminants of integrable differential 

 equations of the first order. — Mr. Tucker (Hon. Sec), com- 

 municated papers by Lord Rayleigh, Sec. R. S. , on point-, line-, 

 and plane-sources of sound. — Note on rationalization, by H. 

 Fortey. — Applications of elliptic functions to the theory of 

 twisted quartics, by Prof. G. B. Mathews. — Prof. Greenhill, 

 F.R. S., communicated remarks on coefficients of induction and 

 capacity and allied problems, in continuation of a former paper 

 (January 1879). — The following were taken as read : electrical 

 oscillations, by Prof. J. J. Thomson, F. R. S. ; and demonstration 

 of the theorem "that the equation x 3 + y z + z 3 — o cannot 

 be solved in integers," by J. R. Holt. 



Zoological Society, June 5.— Dr. Edward Hamilton, Vice- 

 President, in the chair. — The Secretary read a report on the 

 . additions that had been made to the Society's Menagerie during 



