96 research outputs found
Notes on the Reversal of the Sodium Line
The reversal of the sodium line may be demonstrated without the use of a slit or a spectroscope. An incandescent lamp having either a carbon or tungsten filament is placed immediately behind a good sodium flame and viewed from a distance of fifteen or twenty inches through a diffraction grating. The first- and second- order spectra, right and left, will both be in view and in the orange-yellow region of each will appear a sharp dark-line image of the filament of the lamp. This image constitutes the dark-line spectrum of the sodium vapor
Ball and Jet in a Vacuum
A report on an experimental and theoretical investigation of the equilibrium conditions for the case of a ball balanced on a jet of water
A Simple Device for Demonstrating the Tempered Scale
The diatomic scale consisting of a succession of eight tones and containing three intervals known as \u27\u27major second intervals,” two known as \u27\u27minor second intervals\u27\u27 and two half-tones, is not adapted to musical instruments of fixed pitch\u27\u27 (e.g. the piano, harp, etc.) for the reason that it does not without a multiplicity of keys (strings) allow of transposition or change of keys
The Moulding Action of Surface Tension on a Free Sheet of Water
A smooth stream of water falling vertically is allowed to strike the center of a small circular plate placed horizontally. The water under these circumstances spreads laterally over the edge of the plate in a thin stream. Under the action of gravity and surface tension this thin bubble-like stream assumes various forms determined by the velocity of the stream impinging upon the plate and the dimensions of the various parts of the apparatus. The bubble may be made to assume a more or less nearly spherical form or, by joining a free water surface below, to shape itself into the form of a bell. The smooth unbroken forms assumed by this film-stream are very striking, affording a beautiful illustration of surface tension effects and give promise of a convenient means of studying certain surface tension phenomena
A New Form of Carbon Arc
A convenient form of carbon arc for experimental and other work may be constructed at small cost in the following manner. Two straight arc-carbons of suitable size are mounted vertically side by side and parallel and separated by two or three millimeters. These carbons are connected to a 110-volt circuit with a resistance of 5 to 10 ohms, more or less, in series. If now the gap between the upper ends of the carbons is momentarily bridged by another carbon rod, an arc will form and remain when the short-circuiting carbon rod is removed
Visible Phase Relations in an A.C. Circuit
By connecting low wattage neon lamps in parallel with the different portions of an alternating current circuit the phase differences in these parts may be made visible by the rise and fall of the glow in the corresponding lamps
A Parallel Carbon Arc for Direct Current
An arc between carbons of equal diameter placed parallel to each other and spaced a small distance apart operates automatically on alternating current and the carbons burn down equally. When supplied with direct current the positive carbon is consumed at a rate approximately twice as great as that of the negative. Therefore to operate the ordinary parallel carbon arc on direct current some provision must be made to move the positive carbon forward, or a larger carbon must be used on the positive side of the circuit
Photomograph
A photometer is arranged in such manner that the screen and the lamp tested are stationary, the standard lamp being adjusted in distance to effect a balance. If the standard is moved by means of a band running over a wheel conveniently near the screen this wheel will revolve through an angle proportional to the distance the standard is moved
In Memoriam: George Ellsworth Thompson; Stephen J. Popoff; Samuel Walker Beyer; Johan Augustus Udden; William Ernest Andrew Slaght; Merrill M. Meyers
Qualitative methods: are you enchanted or are you alienated?
Copyright © 2007 SAGE Publications. Author's draft version; post-print. Final version published by Sage available on Sage Journals Online http://online.sagepub.com/Since the last report on qualitative methods
(Crang, 2005), many of the practical procedures
of doing qualitative research remain the
same. Human geographers continue to study
texts, to conduct interviews, to convene focus
groups and to engage in ethnography. Indeed,
it is hard, though perhaps not impossible,
to imagine what a radically new form of
qualitative research practice might look like.
So, for the time being, this suite of methods
remains the backbone of qualitative research in
human geography. Yet we would like to contend
that, while these activities continue as
before, there are changes in the way they are
being conceived and carried out, and related to
this there are transformations in the way these
methods are being used to make claims to
understanding and intervening in the world. In
the first of our three reports, it is this link
between qualitative methodologies and interpretative
strategies we would like to reflect on
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