scholarly journals XXXVIII. Experimental researches on the strength of pillars of cast iron from various parts of the Kingdom

1857 ◽  
Vol 147 ◽  
pp. 851-899
Keyword(s):  
Cast Iron ◽  
Royal Society ◽  
Leisure Time ◽  
Point Of View ◽  
Practical Point ◽  
Large Size ◽  
The Subject ◽  
Pass Through ◽  
Experimental Researches

Having in the year 1840 offered to the Royal Society an extensive research upon this subject, which was honoured with the kindest notice of the Society, I felt grateful for the reception it had met with; and though in its preparation it had occupied my leisure time for some years, and contained the results of as many as 277 experiments, which I had made to prove the conclusions arrived at in it, I was still very anxious to improve and extend it. Indeed the importance of the subject would seem to justify every effort I could make for the purpose, when it is considered that a large portion of the houses, warehouses and shops in London, Manchester, Liverpool and throughout the country, depend for their principal supports upon iron pillars, which frequently appear very thin for the weight they have to bear, and being hollow do not allow us to judge from their appearance how small a quantity of metal they have in them, or in other words, whether the building is abundantly strong, or is ready to fall down and crush the persons within it, as has frequently happened to warehouses and other buildings dependent on iron supports. Some of the pillars are made to pass through more than one story, or even are based on the foundation, and support an intermediate floor and the roof. The importance of the subject, in a practical point of view at least, rendered it desirable that a number of pillars of large size should be broken, to obtain data for the application of the principles established in the preceding research; but this was impracticable at that time, notwithstanding the liberality of Mr. Fairbairn, who bore the expense of that inquiry. For by Mr. Fairbairn’s lever then used, more than 18 tons could not be safely applied, and the iron box or frame in which the pillars were broken did not admit pillars of greater length than 7½ feet; but the laborious inquiry in which I was afterwards engaged by Mr. Stephenson, for investigating the properties of the Menai and Conway tubular bridges (that over the Conway in particular), required larger and more powerful apparatus than the preceding, and I can now apply more than three times the pressure formerly used, and break pillars of 10 feet long, and any shorter lengths, with even more accuracy than before.

XX. Experimental researches on the strength of pillars of cast iron, and other materials

1840 ◽  
Vol 130 ◽  
pp. 385-456 ◽  
Keyword(s):  
Cast Iron ◽  
Iron And Steel ◽  
Wrought Iron ◽  
Mechanical Philosophy ◽  
Crushing Force ◽  
The Subject ◽  
Pass Through ◽  
Experimental Researches ◽  
Full Investigation

When we consider to what extent pillars of iron and of timber are used for the support of building's, and reflect that there are no satisfactory rules by which to measure the strength of pillars, it becomes a matter of great importance to obtain such rules by means of experiment, and, if possible, to discover the laws on which they are founded. A feeling of this kind, heightened by the remarks of Dr. Robison, in his Mechanical Philosophy, and by the strongly-expressed opinion as to our want of such knowledge by Mr. Barlow, led me to wish to undertake the inquiry. I mentioned the matter, therefore, to my friend Mr. Fairrairn, who, with that liberality which I have experienced from him on former occasions, at once put every means of a full investigation into my hands. He expressed a wish that I should extend the inquiry to pillars of various kinds, ancient as well as modern; and leave no part of the subject in uncertainty for want of experiments sufficiently varied and extensive. Thus freed from restraint, I endeavoured, in my wish to acquire the requisite information, to forget the expense to which I put my friend, and have made every effort to render the experiments at least ample, correct, and useful. The pillars on which the experiments were made, were mostly of cast iron, as being the material in most general use; but some were of wrought iron and steel, and others of wood. In the earlier experiments, the pillars used were uniform cylinders, either with their ends rounded, so that the crushing force might pass through the axis, or with flat and parallel ends, so that the pillar, when placed between two perfectly parallel crushing surfaces, might have its ends completely bedded against them.

scholarly journals Evaluating Microarray-based Classifiers: An Overview

2008 ◽  
Vol 6 ◽  
pp. CIN.S408 ◽  
Author(s):  
A.-L. Boulesteix ◽  
C. Strobl ◽  
T. Augustin ◽  
M. Daumer
Keyword(s):  
Variable Selection ◽  
Error Rate ◽  
Classification Accuracy ◽  
Point Of View ◽  
Class Prediction ◽  
Practical Point ◽  
Classifier Evaluation ◽  
The Subject ◽  
Accuracy Measures ◽  
Validation Strategy

For the last eight years, microarray-based class prediction has been the subject of numerous publications in medicine, bioinformatics and statistics journals. However, in many articles, the assessment of classification accuracy is carried out using suboptimal procedures and is not paid much attention. In this paper, we carefully review various statistical aspects of classifier evaluation and validation from a practical point of view. The main topics addressed are accuracy measures, error rate estimation procedures, variable selection, choice of classifiers and validation strategy.

scholarly journals II. Experimental researches on the strength of pillars of cast iron

1857 ◽  
Vol 8 ◽  
pp. 318-321
Keyword(s):  
Cast Iron ◽  
The Third ◽  
Pass Through ◽  
Experimental Researches

In a previous paper on this subject (Philosophical Transactions, 1840), I had shown,—1st, that a long circular pillar, with its ends flat, was about three times as strong as a pillar of the same length and diameter with its ends rounded in such a manner that the pressure would pass through the axis, the ends being made to turn easily, but not so small as to be crushed by the weight; 2nd, that if a pillar of the same length and diameter as the preceding had one end rounded and one flat, the strength would be twice as great as that of one with both ends rounded; 3rd, if, therefore, three pillars be taken, differing only in the form of their ends, the first having both ends rounded, the second one end rounded and one flat, and the third both ends flat, the strength of these pillars will be as 1—2—3 nearly. The preceding properties having been arrived at experimentally, are here attempted to be demonstrated, at least approximately.

scholarly journals III. Experimental researches in electricity. —eighteenth series

1843 ◽  
Vol 133 ◽  
pp. 17-32 ◽  
Keyword(s):  
High Pressure ◽  
Royal Society ◽  
Atmospheric Electricity ◽  
Glass Tube ◽  
Direct Relation ◽  
High Pressure Steam ◽  
Change Of State ◽  
Pressure Steam ◽  
The Subject ◽  
Experimental Researches

2075. Two years ago an experiment was described by Mr. Armstrong and others, in which the issue of a stream of high pressure steam into the air produced abundance of electricity. The source of the electricity was not ascertained, but was supposed to be the evaporation or change of state of the water, and to have a direct relation to atmospheric electricity. I have at various times since May of last year been working upon the subject, and though I perceive Mr. Armstrong has, in recent communi­cations, anticipated by publication some of the facts which I also have obtained, the Royal Society may still perhaps think a compressed account of my results and con­clusions, which include many other important points, worthy its attention. 2076. The apparatus I· have used was not competent to furnish me with much steam or a high pressure, but I found it sufficient for my purpose, which was the in­vestigation of the effect and its cause, and not necessarily an increase of the electric development. Mr. Armstrong, as is shown by a recent paper, has well effected the latter. The boiler I used, belonging to the London Institution, would hold about ten gallons of water, and allow the evaporation of five gallons. A pipe 4½ feet long was attached to it, at the end of which was a large stop-cock and a metal globe, of the capacity of thirty-two cubic inches, which I will call the steam-globe , and to this globe, by its mouth-piece, could be attached various forms of apparatus, serving as vents for the issuing steam. Thus a cock could be connected with the steam-globe, and this cock be used as the experimental steam-passage; or a wooden tube could be screwed in; or a small metal or glass tube put through a good cork, and the cork screwed in; and in these cases the steam way of the globe and tube leading to the boiler was so large, that they might be considered as part of the boiler, and these terminal passages as the obstacles which, restraining the issue of steam, produced any important degree of friction.

XIII. Experimental researches in voltaic electricity and electro-magnetism

1832 ◽  
Vol 122 ◽  
pp. 279-298 ◽  
Keyword(s):  
Experimental Investigation ◽  
Royal Society ◽  
Physical Science ◽  
The Subject ◽  
Experimental Researches ◽  
Made In

The splendid discoveries which have lately been made in magnetism and electro-magnetism have so much engaged the attention of philosophers, that the theory and laws of action of voltaic electricity, no longer possessing the charms of novelty, have been entirely neglected. The subject appearing to me full of interest, and lying at the very foundation of a large portion of physical science, induced me to undertake an experimental investigation of some of the most important points connected with it, the result of which I have the honour of laying before the Royal Society.

Microstructure of highly dense Ba2YCu3O7-δ superconductive materials

1989 ◽  
Vol 47 ◽  
pp. 188-189
Author(s):  
K. Park ◽  
T. Yamamoto ◽  
M. Green ◽  
T. Hasegawa ◽  
K. Kishio ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Research And Development ◽  
Superconducting Transition Temperature ◽  
Ceramic Materials ◽  
Point Of View ◽  
Boiling Temperature ◽  
Superconducting Transition ◽  
Practical Point ◽  
The Subject

Since the breakthrough discoveries by Bednorz and Muller and Wu et al., superconductivity in Cu-O based ceramic materials has been the subject of tremendous research and development interest. In particular, the Ba2YCu3O7-δ type oxide is very important from a practical point of view, since it has a superconducting transition temperature (Tc) around 90K, which is above the liq. N2 boiling temperature.

scholarly journals V. Experimental researches on the functions of the mucous membrane of the gall-bladder, principally with reference to the conversion of Hepatic into Cystic bile

1857 ◽  
Vol 8 ◽  
pp. 133-140
Keyword(s):  
Gall Bladder ◽  
Physical Properties ◽  
Mucous Membrane ◽  
Royal Society ◽  
Hepatic Bile ◽  
Pathological Conditions ◽  
Mucous Membranes ◽  
The Subject ◽  
Experimental Researches ◽  
Chemical Experiment

Referring to the well-known difference in taste and other physical properties between the bile as it immediately proceeds from the liver and the same fluid after it has been retained for a time in the gallbladder, the author observes, that the nature of this difference and the agency by which it is effected, are questions which have not yet met with the attention they deserve, and that he had accordingly been led to make them the subject of experimental inquiry. As, however, it is only on rare occasions that the hepatic bile can he procured in quantity sufficient for chemical experiment, and then only at the risk of its being altered by pathological conditions of the secreting organ, the author considers that, however clearly individual facts on the subject may be demonstrated, any deductions made therefrom must be referred to the lower department of probable evidence; and it is with this reservation that he lays his conclusions before the Royal Society, whilst, at the same time, he believes that, so far as the nature of the case admits, he has been able to elicit a new fact respecting the mucous membrane of the gallbladder, which may lead to the better comprehension of the functions of mucous membranes generally.

I. On the electromotive properties of the leaf of dionæa in the excited and unexcited states

1882 ◽  
Vol 33 (216-219) ◽  
pp. 148-151
Keyword(s):  
Royal Society ◽  
Lower Layer ◽  
Electric Properties ◽  
Cylindrical Cell ◽  
Mechanical Excitation ◽  
Du Bois ◽  
The Subject ◽  
Experimental Researches

The paper consists of five parts. Part I is occupied by the examination of two experimental researches, relating to the subject, which have been published in Germany since the date of the anthor’s first communication to the Royal Society in 1873, namely, that of Professor Munk on Dionæa, and of Dr. Kunkel on electromotive action in the living organs of plants. According to Dr. Munk, the electric properties of the leaf may be explained on the theory that each cylindrical cell of its parenchyma is an electromotor, of which the middle is, in the unexcited state, negative to the ends, and that on excitation the electromotive forces of the cells of the upper layer undergo diminution, those of the lower layer an increase. He accounts for the diphasic character of the electrical disturbance which follows mechanical excitation by attributing it to the opposite electromotive reactions of the two layers of cells. According to this theory, the cells resemble in their properties the “electromotive muscle-molecules” (“Unter-suchungen,” vol. i, p. 682, 1848, of du Bois Reymond) differing from them in so far that their poles are positive instead of being negative to their equatorial zones. Professor Munk has constructed a schematic leaf in which the cells are represented by zinc cylinders with copper zones. A schema so made is said by him to have the electromotive properties of the unexcited leaf. Dr. Kunkel’s experiments have for their purpose to show that all the electromotive phenomena of plants may be explained as consequences of the movement of water in the organs at the surfaces of which they manifest themselves.

scholarly journals XXI. Experimental researches on atomic weights

1833 ◽  
Vol 123 ◽  
pp. 523-544 ◽  
Keyword(s):  
First Principles ◽  
Atomic Weight ◽  
Point Of View ◽  
Relative Accuracy ◽  
The Other ◽  
Present Communication ◽  
Present Essay ◽  
The Subject ◽  
Important Object ◽  
Experimental Researches

The present communication may be viewed as the continuation of an Essay on the Composition of the Chloride of Barium, which was honoured with a place in the Philosophical Transactions for the year 1829. In resuming the subject after such a long interval, I feel it right to apologize to the Society for the unfinished state in which that Essay has hitherto been left,—an omission far from voluntary, and entirely due to circumstances not subject to my own controul. In one point of view, however, the delay has been advantageous: it has afforded an opportunity to chemists to verify or correct the results contained in my first Essay, and has enabled me to repeat and extend my researches. The object which I proposed to myself in commencing the present inquiry, was to re-examine some of those estimates which chemists have occasion to use continually as elements in their calculations, and to confide in as the foundation of their doctrines. With this view I undertook to determine the relative accuracy of the atomic weights which the British and Continental chemists respectively employ; and several circumstances induced me to begin by analysing the chloride of barium. Dr. Thomson, on whose experiments the British chemists relied, had obtained so many of his results by means of the chloride of barium, that any material error in the constitution of that compound would necessarily vitiate a large part of his table of equivalents; and if, on the other hand, the estimate of Dr. Thomson proved to be correct, an important error would be chargeable against Berzelius, whose numbers are very generally adopted on the Continent. The result of the inquiry is now well known: the source of fallacy, pointed out in my first communication, has been admitted by Dr. Thomson in the new edition of his System of Chemistry, and he has accordingly changed the equivalent of barium from 70 to 68. The inevitable consequence of this change must be apparent to every one who is acquainted with the method of analysis so frequently resorted to by Dr. Thomson. Many of the experiments described in his First Principles of Chemistry are now at irreconcilable variance with each other, and, if relied upon at all, subvert the conclusions which they once appeared to establish. Nor can those parts of his work which are not subject to this criticism be safely applied to the purposes of science. His view, for instance, of the composition of the compounds of oxygen with phosphorus, arsenic, and antimony, has been lately abandoned by himself; and in the course of the present Essay I shall have occasion to prove, that the atomic weights which he has employed for silver and chlorine are likewise inadmissible. His analysis of sulphate of zinc, which was made, to use Dr. Thomson’s own words, “the foundation on which he endeavoured to rear the whole subsequent doctrine of the atomic weight of bodies,” is peculiarly objectionable. Besides being vitiated by his error in the equivalent of barium, the oxide of zinc was determined by a method which involved an error in principle, and was in practice so complex as to be unfit for the extremely important object which it was intended to serve.

scholarly journals On the structure of the human placenta and its connection with the uterus

1837 ◽  
Vol 3 ◽  
pp. 75-77
Keyword(s):  
Satisfactory Result ◽  
Royal Society ◽  
Internal Surface ◽  
Gravid Uterus ◽  
John Hunter ◽  
The Subject ◽  
Pass Through ◽  
Vascular Connections ◽  
Arteries And Veins ◽  
True Structure

In the year 1780 Mr. John Hunter presented a paper to the Royal Society, in which he laid claim to the discovery of the true structure of the placenta, and of its vascular connections with the uterus. From the appearances which he observed in a preparation of the gravid uterus, after both the veins and arteries had been injected, and a longitudinal incision made through the anterior parietes of the uterus where the placenta adhered to its internal surface, he was led to conclude that the arteries which are not immediately employed in conveying nourishment to the uterus go on towards the placenta, and proceeding obliquely between it and the uterus, pass through the decidua without ramifying; and that just before entering the placenta, after making two or three spiral turns, they open at once into its spongy substance. The corresponding veins he represents as commencing from the spongy substance of the placenta by wide mouths, and after passing obliquely through the decidua, entering the substance of the uterus and immediately communicating with the proper veins of that organ. Dr. William Hunter’s description of the same vessels accords with that of his brother. He regards the placenta as consisting of two distinct parts, namely, an umbilical portion which belongs to the foetus, and a uterine portion, which belongs to the mother, each having its peculiar system of arteries and veins; and he supposes that while, in the fœtal portion, the arteries and veins form continuous canals, these two sets of vessels communicate, in the uterine portion, by the intervention of cells, into which the arteries terminate, and from which the veins begin. The subject was afterwards investigated by Noortwych, Rœderer, and Haller, but without any satisfactory result; and the doctrines laid down by the Hunters were generally acquiesced in by subsequent anatomists.

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