scholarly journals XVIII. On a general method of producing exact rectilinear motion by linkwork

1875 ◽  
Vol 23 (156-163) ◽  
pp. 565-577 ◽  
Keyword(s):  
Accurate Result ◽  
British Association ◽  
Rectilinear Motion ◽  
Parallel Motion ◽  
The Subject ◽  
General Method

Since the invention by James W att, in 1784, of the 3-bar linkwork known as “Watt’s Parallel Motion,” which gives an approximate rectilinear motion, many attempts have been made to obtain a more perfect solution of the problem how to obtain accurate rectilinear motion by means of linkwork. Professor Tchebicheff succeeded in obtaining a 3-bar link-work giving a much closer approximation to a true result; but in his case, as in that of others, the solution is only approximate, and it may be, in fact, shown that with 3 bars an accurate result cannot be obtained. It was not until 1864 that the problem was solved; in that year M. Peaucellier made his memorable discovery of an accurate 7-bar solution; and in 1874, when the subject was brought prominently forward in England by Professor Sylvester, Mr. Hart, in a paper read before the British Association, gave a solution by means of 5 bars. Both these linkworks, as is now well known, depended upon the inversion of a circle with respect to a point on its circumference.

The Recent Geology of the Northern Fayum Desert

1927 ◽  
Vol 64 (9) ◽  
pp. 386-410
Author(s):  
Elinor W. Gardner
Keyword(s):  
British Association ◽  
Preliminary Account ◽  
The Subject

A preliminary account of the subject of this paper was given before Section H of the British Association at the Oxford meeting in 1926 (1, 2).

scholarly journals XIX.—Magnetization and Resistance of Nickel Wire at High Temperatures. Part II.

1907 ◽  
Vol 45 (3) ◽  
pp. 547-554
Author(s):  
C. G. Knott
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Electrical Resistance ◽  
British Association ◽  
Nickel Wire ◽  
Present Communication ◽  
Association Meeting ◽  
The Subject ◽  
The Wire

The experiments which form the subject of the present communication were carried out two years ago, and supplement results already published. A brief note of some of the results was read before the Society in June 1904, and was also read before the British Association Meeting at Cambridge in August of the same year.The previous paper discussed the effect of high temperature on the relation between electrical resistance and magnetization when the wire was magnetized longitudinally, that is, in the direction in which the resistance was measured.The present results have to do with the effect of high temperature on the relation between resistance and magnetization when the magnetization was transverse to the direction along which the resistance was measured.

Toxæmia in the Etiology of Mental Disease. a Discussion opened

1902 ◽  
Vol 48 (202) ◽  
pp. 434-450 ◽  
Author(s):  
T. S. Clouston
Keyword(s):  
Nerve Cell ◽  
General Trend ◽  
Mental Disease ◽  
The Other ◽  
British Association ◽  
Younger Men ◽  
Full Knowledge ◽  
The Subject ◽  
Definition Of ◽  
Do So

Dr. Clouston said that when he suggested toxæmia to the secretary as a suitable subject for a discussion at this meeting he had not intended to be the first speaker, because his object was to bring out more fully the views of the younger members who had recently committed themselves so strongly to the toxæmic and bacterial etiology of insanity, and so to get light thrown on some of the difficulties which he and others had felt in applying this theory to many of their cases in practice. It was not that he did not believe in the toxic theory as explaining the onset of many cases, or that he under-rated its importance, but that he could not see how it applied so universally or generally as some of the modern pathological school were now inclined to insist on. He knew that it was difficult for those of the older psychological and clinical school to approach the subject with that full knowledge of recent bacteriological and pathological doctrine which the younger men possessed, or to breathe that all-pervading pathological atmosphere which they seemed to inhale. He desired to conduct this discussion in an absolutely non-controversial and purely scientific spirit. To do so he thought it best to put his facts, objections, and difficulties in a series of propositions which could be answered and explained by the other side. He thought it important to define toxæmia, but should be willing to accept Dr. Ford Robertson's definition of toxines, viz., “Substances which are taken up by the (cortical nerve) cell and then disorder its metabolism.” He took the following extracts from his address at the Cheltenham meeting of the British Association (1) as representing Dr. Ford Robertson's views and the general trend of much investigation and hypothesis on the Continent.

VI.—British Geological Photographs

1897 ◽  
Vol 4 (1) ◽  
pp. 31-37
Author(s):  
W. W. Watts
Keyword(s):  
United Kingdom ◽  
British Association ◽  
Large Collection ◽  
The United Kingdom ◽  
Private Control ◽  
The Subject

A year ago, by the decision of the Council of the British Association, there was sent to the Museum of Practical Geology a large collection of photographs mainly taken with a view of illustrating, in the most permanent and unbiassed way at present possible, the features and phenomena of geological interest in the United Kingdom. The project of forming such a collectionoriginated with Mr. O. W. Jeffs in 1888, when he read a paperon the subject at the British Association at Bath, in which hepointed out the utility of such a collection and the necessity for forming it. When a committee was appointed in the followingyear he undertook the management of the work, and he has carriedit ou for seven years with indefatigable industry and scrupulou scare, only relinquishing it when the size of the collection beganto exceed the capabilities of private control, and when his own lackof leisure no longer permitted him to devote the requisite time andattention to its custody.

3. Researches in Hydrodynamics. Second Memoir. On Waves

1845 ◽  
Vol 1 ◽  
pp. 433-435 ◽  
Author(s):  
J. Scott Russell
Keyword(s):  
British Association ◽  
Complete Form ◽  
The Subject

The object proposed by the author of this paper, was to present, in a complete form, the results of investigations into the phenomena of Waves, in which he had been engaged for several years. A part of the experiments referred to in the paper, had been carried on by Sir John Robison, conjointly with the author of this paper, as a Committee of the British Association. The others were new, and had been carried on by himself, for the purpose of completing and giving that systematic form to our knowledge of the subject, which was attempted in this paper.

scholarly journals VI. Electrification of air, of vapour of water, and of other gases

1898 ◽  
Vol 191 ◽  
pp. 187-228 ◽  
Keyword(s):  
Royal Society ◽  
Atmospheric Electricity ◽  
British Association ◽  
Present Communication ◽  
The Subject

1. In this paper we describe a long series or experiments on the electrification of air and other gases, with which we have been occupied from May, 1894, up to the present time (June, 1897). Some results of our earlier experiments, and of preliminary efforts to find convenient methods of investigation, have from time to time been communicated to the Royal Society, the British Association, and the Glasgow Philosophical Society. 2. The method for testing the electrification of air, which we used in our earliest experiments, was an application of the water-dropper (long well-known in the ordinary observation of atmospheric electricity). Its use by Maclean and Goto, in 1890, led to an interesting discovery that air in an enclosed vessel, previously non-electrified, becomes electrified by a jet of water falling through it. An investigation of properties of matter concerned in this effect, related as it is to the “development of electricity in the breaking up of a liquid into drops,” which had been discovered by Holmgren as early as 1873, and to the later investigations and discoveries described by Lenard, in his paper on the “Electricity of Waterfalls,” forms the subject of 25-37 of the present communication.

scholarly journals Note on Heuslerʼs magnetic alloy of manganese, aluminium, and copper

1906 ◽  
Vol 77 (516) ◽  
pp. 256-259 ◽  
Keyword(s):  
Magnetic Properties ◽  
British Association ◽  
Magnetic Alloy ◽  
Physical Laboratory ◽  
Iron Nickel ◽  
The Subject

In 1903 Fr. Heusler published the discovery of an alloy consisting of manganese, aluminium, and copper, which, in spite of the fact that it contained none of the so-called magnetic metals, iron, nickel, or cobalt, possessed striking magnetic properties. Short accounts of work on the subject by Heusler and some other experimenters appeared, but on the whole the discovery seems to have aroused comparatively little interest in this country before August, 1904, when R. A. Hadfield exhibited a specimen of the alloy at the Cambridge meeting of the British Association. At the beginning of the winter session 1904 an attempt was made to obtain some of this alloy for the Physical Laboratory of Glasgow University, with the view of determining magnetic curves for the material, and of otherwise extending our knowledge of this interesting manganese bronze.

Modes of Explanation in the Aristotelian Mechanical Problems

2009 ◽  
Vol 14 (1-3) ◽  
pp. 22-42 ◽  
Author(s):  
Jean De Groot
Keyword(s):  
Basic Principle ◽  
Explanatory Power ◽  
Circular Motion ◽  
Rectilinear Motion ◽  
Posterior Analytics ◽  
Central Argument ◽  
Euclid’S Elements ◽  
General Method

AbstractScholars have been puzzled by the central argument of MP 1 where the author addresses the basic principle behind the balance and lever. It is not clear what is intended to provide the explanation—the dynamic concepts of force and constraint or the geometrical demonstration. Nor is it clear whether the geometrical part of the argument carries any logical force or has value as a proof. This paper makes a case for the cogency of the argument as a kinematic, not dynamic, account. MP 1 proceeds systematically as it extends the explanatory power of the parallelogram of movements from rectilinear motion to circular motion. Euclid's Elements I.43 provides insight on the author's procedure. His general method is demonstrative, as described in Posterior Analytics I.1.

Synthesis of Rectilinear Motion by Mechanical Harmonic Function Generators

1962 ◽  
Vol 84 (1) ◽  
pp. 135-143
Author(s):  
Bernard W. Shaffer ◽  
Irvin Krause
Keyword(s):  
Fourier Series ◽  
Harmonic Function ◽  
Rectilinear Motion ◽  
Function Generators ◽  
General Method

A general method is presented for generating controlled rectilinear motion to any desired accuracy. The required motion is expressed in terms of a Fourier series whose coefficients are shown to be related to the governing dimensions of a plane mechanism. The mechanism may be designed to generate enough terms of the Fourier series to satisfy any desired accuracy. The technique is then used for a particular problem to illustrate its application and the method by which the error of approximation may be evaluated.

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