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this is the second communication from Mr. Wicksteed on the same subject. The two are valuable additions to our knowledge on the subject. The water raised was weighed and measured. The weights raised in the stamping machinery were also accurately ascertained, and a comparison instituted between the duty of the single engine in raising water and of the double acting and crank engines in working stamps.

The communication by Mr. Henwood is remarkable for the extreme minuteness of detail with which the observations were conducted; the communication consists of two parts, the one on the quantity of steam employed and the mode of its distribution on the working stroke, the other on the duty performed with a given quantity of fuel. Under the former the Indicator is accurately described, and the evidence furnished by the diagrams explained. Under the latter is exhibited one of the most valuable specimens of detailed observations on record. It is a peculiar feature in the system pursued by Mr. Henwood, that he never interfered with the ordinary working of the engine; he observes with accuracy what is going on. Thus his paper is a record of observation in the highest sense of the term. It is of importance to practical men to keep in mind a distinction which has been often insisted on betwixt observation and experiment. In the former, the phenomena which are going on are noted, as they go on, the circumstances under which they occur being untouched-in the latter, the phenomena are produced for the purpose of the experiment. The former consequently requires great care in referring effects to their proper causes, the latter in guarding against the results being influenced by the circumstances necessary for the production of the phenomena. The two are distinct, each requires their respective talents, the former would lead a Newton to the law of Gravitation, and guide a Smeaton in the construction of an Edystone; the latter, a Watt and a Black to a knowledge of the properties of Steam; and the two combined a Davy, to the construction of a Safety Lamp.

In the communication of your Member, Mr. Parkes, we have an instance of both these methods combined; he observed what was going on under particular circumstances of evaporation, and then having altered the circumstances recorded the results of these experiments. The researches of this author led him to push slow combustion to its utmost limits. It would be foreign to the object of this report to trespass on the time of the meeting, further than to remark, that the contents of this paper may furnish many useful hints to the practical Engineer in the management of the

fires of his Steam Boilers, and to the theorist some important facts towards a true theory of combustion.

The Council have also awarded a Silver Medal to the communications of your Associate, Lieut. Denison, on the strength of American Timber, and of your Member, Mr. Bramah, on the strength of Cast Iron. Each of these communications must be viewed as valuable additions to our knowledge. The series of experiments by Lieut. Denison was undertaken by that talented officer when stationed abroad, with a view of establishing some proportion betwixt the strength of different kinds of American Timber, and of affording a means of comparing it with European. It is a peculiar feature in these experiments, that the effect of time in increasing the deflection is noted. After the elastic limit is passed, the deflection increases with the time which the beam is loaded. The amount of this increase is recorded in most of these experiments. The Council cannot but regret, that Lieutenant Denison should have returned to this country before the very extensive series which he had contemplated, and for which he had made preparation, was complete; his intention of determining the change of strength and the amount of shrinkage betwixt green and dry was thus unfortunately frustrated, and they most earnestly concur with him in the expression of hopes, that officers and others employed in the colonies will be induced to turn their attention to this subject. They point out the above communication with especial pleasure, as an example to other Military Engineers, of the very valuable services which their opportunities will enable them to render to the science of the Civil Engineer.

The other communication by Mr. Bramah is also a valuable addition to our knowledge. Undertaken with a view of verifying the principles assumed in the widely circulated work of Tredgold, on Cast Iron, this series surpasses every other series in existence in its extent-the number of experiments being nearly 1500; and in the care taken to ensure accuracy, since two similar specimens of each beam were made the subject of experiment,

The principles, with the view of establishing which this series of experiments was undertaken, are, that the forces of compression and extension are equal within the elastic limit, and that consequently a triangular beam, provided it is not loaded beyond this limit, will have the same amount of deflection whether the base or apex be uppermost, and a flanged beam the same deflection whether the flange be at the top or the bottom.

This communication is accompanied by some valuable observations by your Associate, Mr. A. H. Renton, pointing out the agreement

which subsists between the experiments and the results of the formulæ of Tredgold. The Council have peculiar pleasure in pointing out the preceding as communications of a kind on which they conceive the Telford Medals may be most worthily bestowed. The undertaking a series of observations and experiments with the view of establishing important physical principles, and from a desire after the truth, is an object worthy of the highest approbation of this Institution.

A Silver Medal has also been awarded to your Member, Mr. Green, for his communication on the Canal Lifts on the Grand Western Canal; to your Member, Mr. Harrison, for his communication on the Drops on the Stanhope and Tyne Railway; and to your Associate, Josiah Richards, for his most elaborate drawing of the Rhymney Iron Works.

The perpendicular lifts erected by Mr. Green on the Grand Western Canal involve some ingenious applications of simple principles, and present many considerations of interest to the Civil Engineer. The principles of their construction are simple, and the economy of construction and saving both in time and water gives them great advantages in certain cases over locks for the purposes of Canal navigation.

The Drops on the Stanhope and Tyne Railway for the purpose of shipping coals present another instance of simple mechanical adaptation. These have several points in common with the lifts just spoken of; the original drawing of these by Mr. Harrison is an exceedingly good example of what drawings of this nature ought to be.

Of the drawing of the Rhymney Iron Works, by Josiah Richards, it would be difficult to speak in too high terms; it is a most elaborate drawing, exhibiting all the details of the manufacture of iron. The Institution has not yet received the description which will be necessary to render the communication complete, but the Council have the gratification of stating, that your Associate, Mr. Rowles, the Chairman of the company, has promised that Mr. Richards shall be furnished with every facility towards completing a communication, which will undoubtedly be a most valuable acquisition to the records already existing in the Institution.

The Council have also awarded a Silver Medal to Francis Whishaw, for his history of Westminster Bridge. Of the great labour and research of Mr. Whishaw in collecting these documents, it would be difficult to speak in adequate terms. The history is extracted from voluminous records contained in the Bridge Office, and you are indebted also to the kindness of your Member, Mr. Swinburne,


for the facilities with which he furnished the Author in the execution of this difficult task. The history of this Bridge, the only one of the old bridges now remaining, is interesting to the general reader, no less than to the Engineer. The difficulties which presented themselves gave rise to contrivances then for the first time brought into use, of which the introduction of caissons is not the least remarkable. The difficulties and progress of the work are well set forth in the reports of Labelye, of which the more interesting are embodied in this communication, and the account of the work furnishes a very complete history of the state of this department of practical engineering a century ago.

This communication, accompanied by an Atlas of eleven drawings, shewing the site and various details of the construction of the bridge, is one of those historical records which it is especially the object of this Institution to collect, and which, from the labour and research employed upon it, called for this mark of approbation of the Council.

The Institution received during last Session from your Member, Mr. Rendel, a very elaborate and beautiful set of drawings, accompanied by a suitable description, of the Torpoint Floating Bridge. This interesting communication is fresh in the recollection of most, and it would be difficult to speak in too high terms of the forethought, skill and design displayed in the construction of these bridges, and the perfect success which has attended their establishment. It does not often happen that the same individual has the genius to invent, and the good fortune to see his invention brought into general use. In this respect Mr. Rendel has been singularly fortunate, as these bridges have been already established in several difficult and dangerous passages. It would be foreign to the present occasion to dwell more at length on this invention; but the Council feel that in awarding a Silver Medal to Mr. Rendel, accompanied by a suitable record of the sense entertained of the benefit conferred by him on the inland communication of the country, this the highest acknowledgment in their power to make is most amply merited.

A Bronze Medal has been awarded to your Associate, Mr. Ballard, for the drawing of his Ice Boat, and description of his method of breaking ice by forcing it upwards; this simple method is applicable at about one-third the labour of the ordinary ice boat. A Bronze Medal has also been awarded to Thomas Macdougal Smith, for his drawing and account of Edwarde's or the Pont-y-tu-prydd Bridge, in South Wales. Mr. Smith being for a short time in the neighbourhood, availed himself of this opportunity to make accurate drawings of this curious and interesting structure. The Council

would point out this as an example of the way in which every young man may, by availing himself of the opportunities afforded by his professional engagements, forward the objects which the Institution has in view; and they would earnestly impress on all young men the importance of availing themselves of such opportunities, and of recording their observations on every work with which they may be connected. This habit is of the greatest advantage to the individual, since only by such habitual self-improvement can any one hope to obtain eminence in the profession.

The Council have also awarded five guineas to Mr. Guy, for his method of making perfect spheres; this great desideratum in the mechanical art has been in a great measure supplied by the ingenuity of this individual, and a simple method furnished of readily producing spheres of metal or other hard substance with a great degree of accuracy.

The preceding are the communications of the last two Sessions to which the Council have awarded Premiums. The Council, in disposing of the premiums placed at their disposal by the munificence of your late President, have endeavoured to select from the great number of communications which have been brought before the Institution such of each class as especially deserved this mark of distinction. They trust that these premiums may act as a stimulus to many to forward to the Institution records of matters of interest to the profession, and that thus the object of the noble benefactor of the Institution will be fully realized.

The Council cannot dwell on the numerous communications received during the last session, of which an ample account will be found in the Minutes of Proceedings; they cannot, however, omit to remark on the great interest of the discussions, and on the value of the record of opinions and facts which is thus obtained. They would especially refer to the discussions on the duty of Steam Engines, and on the explosions of Steam Boilers, as having led to the collection of much valuable matter; the practice of recording the minutes of conversation is almost peculiar to your Institution, and is calculated in an especial manner to forward the interests of practical science.

The Council, in reviewing the events of the past year, cannot omit Life of to express their gratification at the publication of the Life and Telford. Works of Telford. Every thing connected with his name is interesting to this Institution, and the Life and Works of so distinguished a man, written by himself, cannot fail to be received with the greatest satisfaction by all who knew him, or are able to appreciate his works. Through the kindness of your Honorary Member, Mr. Rickman, the Editor of the Life and Works, and acting executor of

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