October 30, 1885.] 



SCIENCE. 



383 



lectureship, at a diminished salary, has been es- 

 tablished in its place. This is filled by Professor 

 Huxley's former assistant, who has long had entire 

 charge of the laboratory teaching, and has just 

 brought out an admirable atlas of elementary 

 biology. It was certainly desirable that his merits 

 should receive the recognition which they de- 

 served. But this might surely have been effected 

 without the infliction of a blow which will be 

 felt in almost every zoological laboratory in the 

 coimtry. 



The Prince of Wales has fixed Monday, Novem- 

 ber 9, for the oflicial closing of the International 

 inventions exhibition. Upwards of three and a 

 quarter million visitors have thus far been ad- 

 mitted. A valuable series of reports, by experts, 

 on the various classes of exhibits, is appearing in 

 the Journal of the Society of arts, which has been 

 from their commencement, the official record of 

 these exhibitions. A scheme is on foot for form- 

 ing, from this exhibition, a floating exhibition on 

 board a large steamer, which is to visit the chief 

 ports ; and in this way the benefits of the exhibition 

 may be extended. 



Among the various agencies for creating an in- 

 terest in the methods and results of scientific in- 

 quiry, on the part of artisans and persons of very 

 limited means, the operations of the Gilchrist 

 educational trust deserve notice. The founder, 

 Dr. Gilchrist, a Scotch silrgeon, left on an exceed- 

 ingly open trust, for the benefit and advancement 

 of scientific learning in any part of the world, the 

 income of certain investments, which have since 

 become very valuable. One of these was a piece 

 of land now in Sydney, Australia, for which he 

 paid $90, which was sold a few years ago by the 

 trustees for $360,000. Part of the trust income is 

 expended in scholarships, chiefly granted to stu- 

 dents in Canada, Australia, India, etc., to enable 

 them to study in England. Another portion is 

 devoted to the delivery of courses of scientific 

 lectures in English and Scotch towns, under local 

 management, but subject to the condition that 

 the charge for admission shall not exceed two 

 cents. These lectures are specially addressed to 

 large popular audiences, often comprising 2,000 

 persons or more. Ten such courses are now run- 

 ning in various towns, and the lecturers engaged 

 in them are Dr. R. S. Ball (Royal astronomer for 

 Ireland), Dr. Dallinger, Prof. W. C. Williamson, 

 Dr. Andrew Wilson, and Mr. Wm. Lant Carpenter. 

 A course usually consists of six lectures, one half 

 on physical subjects, the other upon biological, 

 and their aim is avowedly to awaken an interest 

 in science. Usually the lecture halls are crowded 

 to their utmost capacity. W. 



London, October 13. 



WASHINGTON LETTER. 



The improvements on the arrangement for pro- 

 tecting the Washington monument from damage 

 by lightning are now being made, and will prob- 

 ably be completed within a week. The disturbed 

 portion of stone-work has been very neatly drawn 

 back into its place, and secured by bolts from 

 within. The changes which are being made, with 

 the hope of avoiding all possible injmy in the 

 future, are essentially as follows : a;\_round the 

 lower part of the aluminium pyramid which ter- 

 minates the shaft has been fitted a sort of collar, 

 from which project eight pointed metallic rods, 

 each about three inches in length. To the cor- 

 ners of this collar four copper rods, about one-half 

 an inch in diameter, are secured, extending do^vn 

 the edges of the fifty-five-foot pyramidal apex. 

 These four rods are joined together at a number 

 of points along their length by horizontal strips of 

 metal, each having a cross-section area nearly as 

 great as that of the half -inch rod, but of different 

 form, so as to fit closely into openings along the 

 junctions of the various layers of masonry, ALL 

 are securely joined to the comer or edge rods ; and 

 along both horizontal and edge rods metaUic 

 points, similar to those surrounding the base of 

 the aluminium apex, will project at right angles 

 to the rods, and at distances of four or five feet 

 from each other. It wfil be seen that the great 

 terminal pyramid will thus be covered with a sort 

 of cage of metal rods, from which will project a 

 large number of small metalhc points. All of the 

 metal thus placed upon the surface has been care- 

 fully plated with gold to prevent discoloration of 

 the stone through the action of the weather on 

 the copper. 



The connection of this external cage with the 

 internal conductor seems to be aU that could be 

 desired. To begin with, from the base of the 

 small aluminium pyramid a copper rod or bolt, 

 one and a half inches in diameter, extends to the 

 base of the capstone, by means of which it is 

 secured to the latter. From the extremity of this 

 rod four rods of copper, each having a diameter 

 of three-fourths of an inch, proceed downward, 

 and, separating at a distance of a few feet from 

 their upper ends, are led to the four middle piers 

 of the h'on structure which carries the elevator 

 and the stairway. This structm-e extends tlu'ough 

 the whole height of the monument up to some dis- 

 tance beyond the five-hundred-foot level. It con- 

 sists, in the main, of eight wrought-non columns, 

 four being six and one-half inches in diameter, and 

 four seven and one-half, and aU tied together 

 through iron braces and stays. In addition to the 

 electrical connection of the exterior cage through the 

 aluminium apex, as above described,* independent 



