Another point of great importance is well brought out in the experiments of John Tyndall (Phil.
The experiments of Tyndall upon precipitated clouds have been already referred to.
Huxley, Tyndall, Cairnes, Mark Pattison, F.
His observations led him to the view that a glacier is an imperfect fluid or a viscous body which is urged down slopes of a certain inclination by the mutual pressure of its parts, and involved him in some controversy with Tyndall and others both as to priority and to scientific principle.
John Tyndall (Sound, lecture vi.
John Tyndall, Sound (5th ed., 1893), originally delivered as lectures, treats the subject descriptively, and is illustrated by a large number of excellent experiments.
Tyndall (5820- Tyndall .
Faraday as a Discoverer, by John Tyndall (Longmans, 1st ed.
JOHN TYNDALL (1820-1893), British natural philosopher, was born in Co.
Tyndall was to a large extent a self-made man; he had no early advantages, but with indomitable earnestness devoted himself to study, to which he was stimulated by the writings of Carlyle.
On the 11th of February 1853, however, Tyndall gave, by invitation, a Friday evening lecture (on "The Influence of Material Aggregation upon the Manifestations of Force") at the Royal Institution, and his public reputation was at once established.
But while Forbes asserted that ice was viscous, Tyndall denied it, and insisted, as the result of his observations, on the flow being due to fracture and regelation.
All agreed that ice flowed as if it were a viscous fluid; and of this apparent viscosity James Thomson offered an independent explanation by the application of pure thermodynamical theory, which Tyndall considered inefficient to account for the facts he observed.
It is unnecessary here to rake among the ashes of this prolonged dispute, but it may be noted that Helmholtz, who, in his lecture on "Ice and Glaciers," adopted Thomson's theory, afterwards added in an appendix that he had come to the conclusion that Tyndall had "assigned the essential and principal cause of glacier motion in referring it to fracture and regelation" (1865).
This method of intermittent sterilization originated with Tyndall, and it was an important contribution to biological science and industrial practice.
In 1876 Tyndall married Louisa, daughter of Lord Claud Hamilton.
Tyndall, The Glaciers of the Alps (1860), Mountaineering in 1861 (1862), and Hours of Exercise in the Alps (1871); J.
Professor Tyndall built a house o the top of Hindhead, setting an example followed by man others.
Tyndall, and in 1851 first professor of chemistry at Owens College, Manchester.
Very interesting modifications of these phenomena are observed when a jet from an orifice in a thin plate (Tyndall has shown that a pinhole gas burner may also be used with advantage) is directed obliquely upwards.
In the hands of Brefeld, BurdonSanderson, de Bary, Tyndall, Roberts, Lister and others, the various links in the chain of evidence grew stronger and stronger, and every case adduced as one of " spontaneous generation " fell to the ground when examined.
Calor, heat), a term invented by John Tyndall to describe an optical phenomenon, the essential feature of which is the conversion of rays belonging to the dark infra-red portion of the spectrum into the more refrangible visible rays, i.e.
According to Tyndall, 9 0% of the radiation from the electric arc is non-luminous.
Owing to the inflammable nature of carbon bisulphide, the plate of rock-salt was found to be hardly a sufficient protection, and Tyndall surrounded the iodine cell with an annular vessel through which cold water was made to flow.
A simpler arrangement, also employed by Tyndall, is to cause the rays to be reflected outwards parallel to one another, and to concentrate them by means of a small flask, containing the iodine solution and used as a lens, placed some distance from the camera.
Since the rays used by Tyndall in these experiments are similar to those emitted by a heated body which is not hot enough to be luminous, it might be thought that the radiation, say from a hot kettle, could be concentrated to a focus and employed to render a small body luminous.
Tyndall used the dark rays from a luminous source, which are emitted in a highly concentrated form, so that it was possible to obtain a high temperature, which was, however, much lower than that of the source.