238 



NA TURE 



\yan. 7, 1886 



the more evident the needs of the Physical Department, which 

 has been obliged to occuiy temporarily parts of four different 

 buildings. The Trustee;, recognising this need, are now erecting 

 a building for a physical laboratory. The new laboratory is to 

 be a handsone building of red brick, trimmed with brown sand- 

 stone, and will occupy a fine site about a block from the other 

 Universitv buildings, on the corner of a quiet little street mid- 

 way between the more important streets, which carry the bulk 

 of the traffic of that region. It will therefore be as free from 

 disturbance from the earth-vibrations as could be expected in a 

 city. 



The building will be 115 feet long by 70 feet broad, and will 

 have four stories besides the basement. In the centre of the 

 building, and below the basement, are several vaults for instru- 

 ments requiring to be u^ed at constant temperature, also a fire- 

 proof vault for storage. In these vaults will be placed Prof. 

 Rowland's dividi-ig-engine, by which the difl'raction-gratings are 

 ruled, and the Rogers- Hond comparator, which has recently be- 

 come the property of the University. In the basement will be 

 rooms for the mechanical workshop, for furnaces, and for piers 

 for instruments requiring great stability. The first floor will 

 include the main lecture-room, which will accommodate 150 

 persons, and rooms for investigations by advanced students in 

 heat and electricity. The second floor will contain mathe- 

 matical lecture-rooms, studies for instructors, and a room for the 

 mathematical and physical library of the University. 



The elementary laboratory will be on the third floor, which 

 will also have rooms for more advanced wirk. The fourth 

 floor will contain rooms for special work in light. 



There will be a tower on the southeast corner of the building, 

 which will have two rooms above the fourth floor. The upper 

 of these will be provided with telescope and dome, and will be 

 a convenient observatory when great steadiness in the instru- 

 ments is not required. There will be power in the building 

 for driving the machinery in the workshop and for runninj the 

 dynamo-machines. A large section of the building is to lie 

 made entirely free from iron. The sash-weights will be of lead, 

 and the gas-pipes of brass. Brackets will be attached to the 

 walls, on which galvanometers and cathetonieters may be 

 placed. In order to avoid the inconvenience of having piers go 

 up through the lower rooms, and yet to secure steadiness, beams 

 have been introduced into the floors, w hich reach from one wall 

 to the other between the regular floor-beams, and do not touch 

 the floor at any point. If, now, a table is made to rest on two 

 of these beams, by making holes in the floor over them to admit 

 the legs of the table, it is entirely undisturbed by any one walk- 

 ing over the flo:)r, except by such motion as is transmitted to the 

 walls. There will also be a small vertical shaft in the wall of 

 the tower, running from top to bottom, in which a mercurial 

 manometer may be set up. 



The vaults for constant temperature have been built witli 

 double walls, so that a current of air may be drawn between 

 them whenever desirable to prevent dampness. It is expected 

 that the iahoratoi-y will be ready by October next. 



The photographic map of the spectrum upon which Prof. Row- 

 land has expended so much hard w oric during the past three years, 

 is nearly ready for publication. The map is issued in a series of 

 seven plates, covering the region from wave-length 3100 to 5790. 

 Each plate is 3 feet long and i foot wide, and contains two 

 strips of the spectrum, except Plate No. 2, which contains three. 

 Most of the plates are on a scale three times that of Angstrom's 

 map, and m definition are more than equal to any map yet pub- 

 lished, at least to wave-length 5325. The 1474 line is widely 

 double, as also are /'g and /J4, while E may be recognised as 

 double by the expert. In the region of the H line these photo- 

 graphs show even more than Lockyer's map of that region. 

 Negatives have also been prepared down to and including the B 

 group, and they may be made ready for publication, one of 

 which shows eleven lines between the D lines. A scale of 

 wave-lengths is printed on each plate, and in no case does the 

 error due to displacement of the scale amount to one part in 

 50,000. The wave lengths of over 200 lines have been deter- 

 mined to within one part in 500,000, and these serve as reference 

 lines to correct any small error in the adjustment of the scale. 

 The great value of such a map lies not only in the fact that it 

 givps greater detail and is more exact than any other map in 

 existence, but that it actually represents the real appearance of 

 the spectrum in giving the relative intensities and shading of 

 groups of lines, so that they are readily recognisable. Tlie 

 photographs were taken with a cincave grating 6 inches in 

 diameter, and having a radius of curvature of 21^ feet, and the 



photographs were taken when the plate was placed directly 

 opposite the grating ; both the sensitive plale and grating being 

 perpendicular to a line joining their centres, and placed at a 

 distance apart equal to the radius of curvature of the grating, 

 the slit being on the circumference of the circle, whoe diameter 

 is the distance between the grating and plate. With this arrange- 

 ment, the spectrum is photographed normal for wave-lengths 

 without the intei-vention of any telescopes or lens systems ; and 

 a suitable scale of equal parts applied to such a photograph at 

 once gives relative wave-lengths. 



Few persons have any idea of the perseverance and patience 

 required to bring such a task to a successful issue. More than . 

 a year was devoted to i)reliminai-y experiments designed to dis- 

 cover the best mode of preparing the plates for the particular 

 regions to be photographed. Hundreds of preparations were 

 tested to find their influence on the sensitised plate^ and the 

 whole literature of photography was ransacked, and every 

 method tested to the utmost, before the work of taking the 

 negatives could begin. 



The Rogers-Bond comparator, which has been already referred 

 to as having been purchased by the University lately, is one of 

 two instruments that were constructed in 1881 by Pratt and 

 Whitney of Hartford, Conn. The general plan and require- 

 ments were made out by Prof. W. A. Rogers of Cambridge, and 

 the drawings and details were worked out by Mr. George M. 

 Bond, then a student at Stevens Institute. The comparator 

 \\'as designed for making exact comparisons of standards of 

 length. The other similar comparator is owned by the Pratt 

 and Whitney Manufacturing Company, and is used by them in 

 testing and constructing their standard gauges. 



The instrument consists essentially of two microscope- 

 carriages, which slide on two parallel cylindrical steel ways 

 between stops, which may be clamped at any point. A carriage 

 entirely independent of the ways on which the microscopes slide 

 supports the two bars to be compared, and is provided with 

 means of accurate and rapid adjustment, by which the bars may 

 be successively brought into position under the microscopes, and 

 the lengths compared by the micrometers attached to the micro- 

 scopes; or one microscope only need be used, and slid first 

 against the stop at one end, and then against that at the other 

 end. The instnmient also affords great facility in determining 

 fractions of a given length with any desired degree of precision. 

 The instrument is one requiring the utmost skill in its con- 

 struction, and it cost several thousand dollars to make it. A full 

 account of this remarkable instrument is given in the P10- 

 cccdifi^s of the American Academy of Arts and Sciences for 

 18S2-S3. K. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 

 The Chancellor of St. Andrew's University (His Grace the 

 Duke of Argyll) has given his sanction to a recent enactment ot 

 the University Court empowering the Senatus to admit to the 

 Science Degrees of the University, students who may have 

 received their education at University College, Dundee. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, December 17, 1885. — " A Preliminary Ac- 

 count of a Research into the Nature of the Venom of the Indian 

 Cobra {Naja tripudiaiis)." By R. Norris Wolfenden, M.D., 

 Cantab, (from the Physiological Laboratory, University Coll., 

 London). Communicated by E. A. Schafer, F. R.S. 



In this account the author refers only to cobra venom, the 

 venom of Na;a iripudians. The dried venom dissolved in water 

 and filtered from accidental particles yields a solution, clear, and 

 usually slightly acid. This solution contains a large amount of 

 proteid. Boiling produces a copious coagidum, and after removal 

 of all coagulum by frequent filtration there is still much proteid in 

 the solution. A fresh solution of the venom is at once precipitated 

 by neutral salts such as MgSo<, NaCl, &c., and also by absolute 

 alcohol. 



The previous valuable labours of Sir Joseph Fayrer {Proc. 

 Roy. Soc, 1873, 1874, 1875, 1878), and Dr. Lauder Bninton 

 and others, have dealt chiefly with the ohysiological side of the 

 question, but have left the chemical nature of these snake 

 venoms still undetermined. 



