November 9, 1899] 



NATURE 



41 



OUR ASTRONOMICAL COLUMN. 



Holmes' Comet (1899 d). 



Ephemeris for I2h. Greenwich Mean Time. 

 1899. R.A. Decl. 



The Coming Meteor Shower.— Much has recently been 

 written respecting the necessary preparations for obtaining 

 photographic record of the Leonids, but hitherto these instruc- 

 tions have only taken into. consideration the determination of 

 the position and appearance of the meteor trail. There must 

 be many, however, who are in a position to attempt to obtain a 

 record of the composition of the meteorites. The only additional 

 apparatus will be either a prism or a diffraction grating. After 

 the camera has been focussed, the prism or grating can be very 

 simply attached to the hood of the lens, and the whole then 

 constitutes a small prismatic camera which will give the spectrum 

 of any meteor whose image falls on the plate. A grating is 

 preferable, as the reduction of the spectrum is more easily made, 

 and there is also the advantage that an ordinary picture of the 

 object is obtained in addition to the spectrum. Practically 

 perfect transmission gratings can now be obtained very cheaply 

 of sufficient size to cover the lenses of ordinary cameras. If a 

 prism is used, it should preferably be set at minimum deviation 

 to allow of subsequent comparisons being made. 



Long Focus Photographic Telescope. — Prof. E. C. 

 Pickering some time ago asked for donations to enable a 

 photographic lens of unusually long focus to be made for the 

 use of the Harvard College Observatory. We hear that now 

 the whole of the necessary amount has been subscribed by 

 anonymous donors, and that a lens of about 12 inches aperture 

 and over 100 feet focal length will probably be ready for trial 

 during the ensuing year. 



Spxular Perturbations of Venus.— Prof. Eric Doolittle, 

 of the Flower Observatory, has completed his investigation of 

 the perturbations of Venus by the computation of those caused 

 by the planet Neptune. The perturbations arising from the 

 six inner planets have beeh published in the Astronomical 

 Journal, Nos. 409, 428, 418, 434, 438 and 465, and the present 

 communication appears in No. 470. 



The planetary elements used have been adapted from Dr. G. 

 W. Hill's " New Theory of Jupiter and Saturn." 



All the equations are given in tabular form, and the 

 variations arising from the combined action of all the disturbing 

 planets are given in the form of six equations, one for each 

 element. 



ENGINEERING PROGRESS AND PROBLEMS. 

 'T'HE eighty-first session of the Institution of Civil Engineers 

 ^ was opened on Tuesday with an address by the president, 

 Sir Douglas Fox. A general survey of engineering progress 

 during the present century was given in the address, the follow- 

 ing being a few of the points to which reference was made : — 



British engineers have two chief bodies of competitors to 

 reckon with — the engineers of the great and growing empire of 

 Germany and those of the United States, who have been 

 thoroughly trained in theory and practice, and are proving their 



NO. 1567, VOL. 61] 



ability and courage by the vast works they originate and carry 



German and other continental engineers are greatly assisted 

 in many ways by paternal Governments, whose officers they 

 generally are, and who lay down valuable regulations, and in 

 many instances establish standards of quality and design. 



American engineers are encouraged by the vast demands of a 

 comparatively new country, in which nature exists on a magni- 

 ficent scale, only equalled by Switzerland and India, and of a 

 rapidly rising civilisation calling loudly for the most recent 

 improvements in locomotion, in building, in lighting, in 

 telephonic and telegraphic communication. 



An important matter demanding careful consideration by 

 civil engineers, if not by the Institution itself, is whether com- 

 petition in the world's race could be facilitated by the establish- 

 ment, upon sufficient authority, of standard specifications for 

 such materials as steel and cement, and the introduction of 

 standard types for bridgework, roofing and other structures 

 frequently occurring in practice, and for locomotives and rollmg 

 stock. 



The question of the adoption of the metric system haW been 

 ably dealt with by others. I therefore only desire to>r6coVd my 

 opinion that it is of the utmost importaitce to the engineers and 

 traders of this empire, that this simple and effective mode of 

 measurement, already in force in almost every other civilised 

 nation, should be introduced here. Having had occasion for 

 many years to work under both systems, I can bear testimony 

 to the great saving of time and of labour effected by the use of 

 the metrical weights and measures, and to the ease with which 

 the system is acquired, even by those trained to use our 

 antiquated and complicated standards. I am strongly of 

 opinion that the two great Anglo-Saxon nations. Great Britain 

 and the United States, must fall into line with the rest of the 

 world in this matter, and it would be a notable and interesting 

 mark of our entry into a new century if, as has already been 

 suggested to our Government, the metric system could be made 

 compulsory as from A. D. 1900. One great obstacle to British 

 designs and manufactures finding their way upon equal terms 

 through the continent of Europe and into the vast empire of 

 China, Japan and elsewhere, would thus be removed, and 

 engineers throughout the world would be thinking and designing 

 upon a basis of like dimensions. 



Nothing has more largely contributed to engineering successes 

 of late years than the introduction of cheap steel of good quality 

 and of high tensile strength, both for rails and for plates and 

 rolled sections. Remarkable uniformity of quality has been 

 attained, and, whilst the life of rails has been greatly increased, 

 structures such as the Forth Bridge have been rendered prac- 

 ticable. At the present time mild steel is almost exclusively 

 used for the construction of ships, thus greatly increasing their 

 carrying capacity. Some anxiety is being caused to engineers 

 by the manifest signs in rails and axles of fatigue after con- 

 siderable wear, and the report of the Board of Trade Committee 

 upon this subject is awaited with much interest. 



With reference to this matter and to other questions involving 

 .scientific research, the resources of this Institution might, I 

 suggest, be advantageously employed. Large numbers of 

 experiments upon steel and other materials have been made 

 with small specimens, but the testing to destruction of full-sized 

 members of bridges and other structures, and experiments upon 

 the effects of impact and of loads running at high speeds have 

 been generally beyond the limits of private enterprise. As a 

 result comparatively few of such records are available, whilst 

 the value to our members would be very great. 



There is no department of engineering which has benefited 

 more by the inventive genius of the century than that of 

 mining. Improved methods of sinking deep shafts, tubbing 

 back water, and winding at high speeds from great depths, 

 have enabled much coal to be opened up. Electricity has 

 been impressed into the service with most beneficial results, 

 not only of economy, but of safety and improved sanitation, 

 and is now largely used for underground haulage, for light- 

 ing, for pumping at the face, and, in the shape of telephones, 

 for communication. In dealing with gold and other ores, 

 chemistry, electrolysis and mechanical engineering have com- 

 bined to reduce cost and waste. Every effort is still necessary 

 on the part of our mining engineers to face the competition, 

 and the labour-saving appliances, not only of Belgmm and 

 Germany, but still more of the United States. It is surely 

 to be regretted that it has been found necessary to obtain so 



