1S46.J 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



317 



town with that eminent scientific navi^tor Admiral Lutke, in whose squadron his Im- 

 perial Hiphness the Grand Duke Constantine was acquiring a knowledge of his maritime 

 duties. Besides the narrative of his former voyagts, Lutke has since published an ac- 

 count of the periodical tides in the Great Northern Ocean and in the Glacial Sea, which 

 I have reason to think is lit;Ie known in this country. Having since e6tal)lished a " hyp- 

 salographe" in the White S"a, and being also occupied from time to time in obsemiions 

 in Behring's Straits, the Russians will soon be able to provide us with other important 

 additions to our knowledge of this subject. Separated so widely as Admiral Lutke and 

 rr. Whtfwell are from each other, it is pleasing to see, that the very recommendation 

 which the last-mentioned distinguished philosopher of the tides has recently suggested to 

 me, as a subject to be encouraged by this Association, has been zealously advocated by 

 the former. Let us hone ihen that this meeting will not pass away without poA'erlully 

 recommending to our own government, as well as to that of his Imperial Majesty, that a 

 systematic and simultaneous investigation of the tides in the Great Ocean, particn-arly 

 in the Northern Pacific, he the object of special expeditions,— a subject (as Admiral 

 Lntke well observes) which is not less worthy of the attention of great scientific bodies 

 than tj.e present inquiries into terrestrial magnetism ; and one which, I may add, this 

 Association will doubtless warmly espouse, since it has such strong grounds for being 

 satisfied with the results which it has already contributed to obtain through its own 

 grants, and by the researches of several of its associates. 



Lastly, in alluding to our foreign attendants, let me say how well our nearest neigh- 

 bours have responded to our call, who. Imitating the example oT their enlightened mo- 

 narch, have proved by their affluence to Southampton, that in the realms of science, as in 

 public affairs, there is that " entente cordiale" between their great nation and our own, 

 of which, at a former meeting, we vvere personally assured by the profound Arago him- 

 self. 



No sooner was it made known that the chair of chemistry at this meeting was to be 

 filled by Michael Faraday, than a compeer worthy of him in the Academy of Sciences of 

 Paris was announced in the person of M- Dumaa. To this sound philosopher it is well 

 known that we owe, not only the discovery of that law of substitution o* types, whicti 

 has so powerfully aided the progress of organic chemistry, but also the successtul appli- 

 cation of his science to the arts and useful purposes of lite ; his great work on that sub- 

 ject, " La Chimie appliqu^e aux Arts," bemg as familiar in every manufactory in England 

 as it is upon the Continent. 



Nor, if we turn from chemistry to geology, can such of us as \vork among the rocks be 

 backward in our expressions of thankfulness, in witnessing the goodly attendance of our 



brethren of the hammer from France, headed by W. , who h;»ve come to examine, 



in our own natural sections of the Isle of Wight, the peculiar development of their Parii 

 basin, the identity of their chalk and our own, the fine sections of our green sand and of 

 the WeaUien formation of Mantell, and to determine with us " in situ" the strict rela- 

 tions of their Neocomian rorks with those peculiar strata which at Atherfield, in the isle 

 of Wight, have been so admirably illustrated by Dr. Fitton and other native geologists, 

 and of which such bez.ntiful and accurate diagrams have bean made by Captain Ibbot- 

 lon. 



It is utterly Impossible that such gatherings together of foreign philosopher* W'th our 

 own should not be productive of much advantage; for he must indeed be a bad statist in 

 science who knows not that numerous are the works of merit which are publislied in 

 periodicals, or in the volumes of societies of one country, which remain altogether un 

 known in aaotharj and still less can be acquainted with the present accelerated march ' f 

 science, who is not awrtn? that the germs of discovery which are lyinp ready in the minds 

 of distant contemporaries must often be brought into action by sucli an interchange of 

 thought. The collision of such thoughts may indeed be compared to the agency of the 

 electric telegraph of ou^ Wheatstone, which concentrates knowledge from afar, and at 

 once unites the extremities of kingdoms in a common circle of intelligence. 



But although the distinguished foreigners to whom I have adverted, and others, in- 

 cluding our welcome associate M. Wartmann, the founder of the Vaudois Society, and 

 jM. Prevost. of Geneva, on whose merits I would willingly dilate if time permitted it, are 

 now collected around us; many, among whom I must name M. rie Caimnnt, the Pre- 

 sident of the French Society for the advancement of Science, have been prevented fro'n 

 honouring us with their presence, because the national meetings in their several countries 

 also occur in the month of September. T^i remedy this inconvenience, I ventured, when 

 addressing you six years ago at the Glasgow meeting, to express the hope, that each of 

 the national FJnropean societies might be led to abstain during one year from assembling 

 in its own country, for the purpose of repairing by its own deputies to a general congress, 

 to be held at Frankfort or other central city under the presidency of the universal Hum- 

 boldt. Had the preparation of the "Cosmos," and other avocations of that renowned 

 individual permitted him to accept this proposition, which I have every reason to believe 

 tlie British Af^sociatiou would have supported, I am convinced that many Iienffits to 

 science would have resulted, and that each nat'onal body, on re-assemb'.ing the following 

 year in its native land, would have more vigorously resumed its research'.s. 



Adhering still "to my project, 1 beg my countrymen and their f ireign friends now pre- 

 sent, to sustain this proposition for centralising in a future year the representatives of 

 the various branches of science of different countries, when they may at once learn the 

 national progresses respectively made, and when, at all events, they can so appoint tlie 

 periods ot their national assemblies as to prevent those simultaneous meetings in France, 

 Germany, Scandinavia, Italy, Switzerland and England, whiLh are so much to be depre- 

 cated as interfering with a mutual intercourse. 



Finally, my fellow-labourers in science, if by our united exertions we have done and 

 are doing good public service, let me revert once more to the place in which we ar*- as- 

 sembled, and express on your part the gratification I know you experience in beuig on 

 this occasion as well supported by tlie noblemeu, clergymen, and landed proprietors 

 around Southampton, as by its inhabitants themselves— an un-on which thusttstifies 

 that the British Association embraces all parties and nil classes of men. 



Seeing near me Her Most Gracious M-ijesty's Secretary of State for Foreign Affairs, the 

 Speaker of the House of Commons, and other persons of high station and very great in- 

 fluence, who willingly indicate by their ))resence the sense they entertain of tlie value of 

 our conferences and researciies, let us welcome these distinguished individuals as living 

 evidences of that good opinion of our countrymen, the possession of which will cheer ns 

 onward in our career. And above all, let us cherish the recollection of the Southimpton 

 meeting which will be rendered memorable in its annals by the presence of the illustrious 

 Consort of our beloved Sovereign, who participating in our pursuits, in many branches of 

 which his Royal Highness is so well versed, thus demonstrates that mir aasociaiiim is 

 truly national, aiid enjoys the most general and effettuat support througliout British so- 

 tiety, from the humblest cultivators of science to the highest personages in the realm. 



Royal Naval Steam-vard, Plymouth — -The total acres of ground to 



be included in th<? establishuient at Morice Town, is about 75 aires. The contractors 

 have new employed on the w. rks 750 men, UO horses, 3 steam-engines, with 12 miles of 

 railway. 6'''0,'i0t) cubic feet of stone {granite and lime-stone) are on the ground, ami they 

 areiiortring seven of the principle quarries of the country. Th- works w II go forward 

 with the greatest rapidity, and it is expected that a steamer will be admitted into une of 

 the basins within three years and a half from this time. The cotier dam, which the en 

 terprisinf? contractors, Messr^ Baker and Son. have undertaken oi' then- own responsi- 

 bility, is 2,000 feet long, within wliich the seawall o( the sa'ne length is to !;e built. '1 here 

 will be two immense basins, the nor- h basin, 650 feet by (;2& feet, and the south basin, 

 fiL'.") feet by otli) feet, each having a depth of 27 feet of water .\t idl times, and will allow of 

 18 first-class vessels to be fitted out, or 2.") ot all classes, exclusive of those in the dock-. 

 The two hasins contain Itj acres. There will be thee large docks; one (the north dock) 

 360 feet long by 94 feet wide for first-rates ; another 40(1 feet lonir by 82 feet wide, fur the 

 largest steamers ; and the third (the south dock) 3U0 feet long by 82 feet wide. 



RBVIEVT. 



Experimental Researches on the Strength and other Proportions of Cast 

 Iron. By Eaton Hodgkinson, F.R.S. London : Weale, 1846. 8vo. pp. 

 200. Five plat(?s. 



The first part of this work which is a new edition of Tredgold's Treatise 

 with additional notes by Mr. Hodgkinson, appeared in 1842; the secontl 

 part now before us is entirely written by Mr. Hodgkinson, and though it is 

 published as a separate volume, the pagination is continued on from the pre- 

 ceding one. The principal distinction between the two works is that the 

 former treated of the effects produced upon bodies by forces small compared 

 with those necessary to produce fracture, whereas the present volume refers 

 almost exclusively to the ultimate strength of cast iron, or the capability of 

 resisting fracture. 



The subject is divided into four parts, the strength to resist, 1st, longi- 

 tudinal tension; 2iid, longitudinal compression; 3rd, transverse pressure 

 (the case of girders) ; 4th, tension ; the course of experiments under each 

 head is explained at length, and the results tabulated: a mathematical in- 

 vestigation of the theory of the strength of beams is also given. 



The first part of the work which considers the tenacity of cast iron occu- 

 pies but a small space, as the subject offers comparatively little difficulty to 

 the experimenter — the following concluding remarks will sufficiently show 

 the nature of the results. 



" With these facts before the reader, he will, I conceive, be unable to see 

 bow the mean tensile strength of cast iron can properly be assumed at more 

 than 7 or 73 tons per square inch ; but some of our best writers have, by 

 calculating the tensile strength from experiments on t!ie transverse, arrived 

 at the conclusion that the strengtii of cast iron is 10, or even 20 tons, or 

 more. Mr. Harlow conceives it to be upwards of 10 tons (Treatise on 

 Strength of Tim'rjer, Cast Iron, &c., p. 222), and Mr. Treugold makes it at 

 least 20 (art. 72 to 76). The reasoning of Mr.Tredgold, by which he arrives 

 at this erroneous conclusion, with others resulting from it, will be examined 

 at length under the head ' Jransverse Strength.' Navier, too, (Application 

 de la Mecanique, article 4,) calculalts the tensile strength of cast iron from 

 principles somewhat similar to those assumed by Tredgold, and finds it much 

 too high." 



In considering longitudinal compression the experiments are divided into 

 two classes, those upon long and those on short pillars, as the former usually 

 broke by bending, and the latter by crushing; and consequently the laws for 

 the two cases wiiiely differ. Under this head we find the foilo'.ving interest- 

 ing results. 



"The strength of a pillar in the form of the connecting rod of a steam 

 engine was found to be very small ; indeed, less than half the strength that 

 tlie same metal wouki have given if cast in the form of an uniform hollow 

 cylinder. The ratio of the strength, a<.-cording to ray experiments, was 

 17573 to 39645. A pillar irregularly tixed, so that the pressure would be iu 

 the direction of the diagonal, is redu-'ed to one-third of its strength, the case 

 being nearly similar to that of a pillar with rounded ends, the strength of 

 which his been shown to he only ^rd of thft of a pillar with flat ends. 

 Trcdgiild, art. 2S3 of his work on Cast Iron, and in his Treatise on Carpen- 

 try, following the idea of Serlio in his Architecture, recommends circular 

 abutting jnints, to lessen the effect of irregularity in the strains upon columns, 

 from settlements and other causes ; but this, we see, is voluntarily throwing 

 away two-thirds of the full strength of the material to prevent what may 

 often be avoided." 



The question of transverse strengtii occupies the greater part of the book. 

 The first point ascertained is how far bars of cast iron will bear the long con- 

 tinued pressure of weights which are not sufficient to break them immedi- 

 ately. The effect of temperature and defect of elasticity are next considered, 

 and lastly the general laws of the transverse strength of beams. The ex- 

 periments instituted are extremely numerous, the results tabulated are de- 

 rived from researches extending over a great number of years, and are of 

 course invaluable. The information given with respect to bars of rectangular 

 section is so full and complete as to almost exhaust the subject ; wiien how- 

 ever Mr. Hodgkinsiia investigates the strength of beams varying in their 

 rectangular section, and endeavours to ascertain the form of uniform strength, 

 he leaves room for further inquiries. Before commenting on this most im- 

 portant part -»f the subject, we must let our author explain for himself the 

 mode of investigation which he has adopted. 



" The ribs in the model were first made equal, as in the beam of strongest 

 form according to the opinion of .Mr. Tredgold (Section IV., art. 37) ; and 

 when a casting had been taken from it, a small portion was taken from the 

 top rib, and attached to the edge of the bottom one. so as to make the ribs 

 as one to two; and when another casting had been obtained, a portion more 

 was taken Irom the top, and attached to the bottom, as before, and a casting 

 got from it, the ribs being then as one to four. In these alterations the 



41 



