In the receiver there is a strong electromagnet, excited by a local current, which has in its circuit two annular air gaps, across which the magnetic field is practically uniform and constant.
In these annular spaces there are suspended by springs two light coils of fine copper wire, capable of being moved vertically, and connected in such a manner as to be traversed by the two variable line currents from the transmitter.
These coils are drawn down, by the magnetic action of the field on the currents in the coils, into the annular spaces, against the pull of the springs, more or less strongly, according to the strengths of the two line currents.
To the brass bottom of the case is attached 'a thin disk of polished hard carbon C, which is slightly less in diameter than the brass bottom, so that the carbon disk almost entirely covers this brass back, leaving only a slight annular space around its edge.
A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.
Such a vascular cylinder is called a haplostele, and the axis containing it is said to be haplostelic. In the stele of the root the strands of tracheids along the lines where the xylem touches the pericycle are spiral or annular, and are the xylem elements first formed when the cylinder is developing.
Each strand of spiral or annular first-formed tracheids is called a protoxylem strand, as distinct from the metaxylem or rest of the xylem, which consists of thick-walled tracheids, the pits of which are often scalariform.
The thin-walled spiral or annular tracheae of the protoxylem allow of longitudinal stretching brought about by the active growth in length of the neighboring living parenchymatous cells of a growing organ.
It is thickened more in some places than in others, and thus are formed the spiral, annular and other markings, as well as the pits which occur on various cells and vessels.
Cases of complete fusion occur in the formation of laticiferous vessels, and in the spiral, annular and reticulate vessels of the xylem.
An ear of another type is found in the swollen second segment of the feeler in many male gnats and midges, the cuticle between this segment and the third forming an annular drum which is connected with numerous nerveendings, while the fine bristles on the more distal segments vibrate in response to the note produced by the humming of the female.
Besides the sugar-refinery already mentioned, there were in Ig00 four tobacco factories, a national printing-press, an annular furnace for brick-burning, an iron-foundry and several blast-furnaces, under the management of the state.
Some of the rubber having been placed in the annular space between the inner cylinder and the outer casing, the former is made to revolve; and the continued kneading action to which the rubber is subjected works it into a solid mass, something like a gigantic sausage.
The cardinal process is prominent, and on each side of the hinge-plate are situated the dental sockets; the loop in Terebratulina becomes annular in the adult by the union of its crural processes (fig.
When light passes through a small circular or annular aperture, the illumination at any point along the axis depends upon the precise relation between the aperture and the distance from it at which the point is taken.
The amplitude of the light at any point in the axis, when plane waves are incident perpendicularly upon an annular aperture, is, as above, cos k(at-r 1)-cos k(at-r 2) =2 sin kat sin k(r1-r2), r2, r i being the distances of the outer and inner boundaries from the point in question.
The integrations may also be effected by means of polar coordinates, taking first the integration with respect to 4) so as to obtain the result for an infinitely thin annular aperture.
The value of C for an annular aperture of radius r and width dr is thus dC =271-Jo(Pp)pdp, (12).
Again, if we compare the complete circle with a narrow annular aperture of the same radius, we see that in the latter case the first dark ring occurs at a much smaller obliquity, viz.
It may be instructive to contrast this with the case of an infinitely narrow annular aperture, where the brightness is proportional to Jo 2 (z).
B2' and this, by § 36, is also the ratio of the kinetic energy in the annular 4,1 interspace between the two cylinders to the kinetic energy of the liquid moving bodily inside r = b.
Considered by itself, with the cylinders held fixed, the vortex sets up a circumferential velocity m/r on a radius r, so that the angular momentum of a circular filament of annular cross section dA is pmdA, and of the whole vortex is pm7r(b2-a2).
The continuity is secured if the liquid between two ellipsoids X and X 11 moving with the velocity U and 15 1 of equation (II), is squeezed out or sucked in across the plane x=o at a rate equal to the integral flow of the velocity I across the annular area a l.
In length; with such coils, and a sufficient annular space in the pan free from obstruction, in order to allow a natural down-current of the cooking mass, while an up-current all round is also naturally produced by the action of the heated worms or coils, rapid evaporation and crystallization can be obtained, without any mechanical adjuncts to require attention or afford excuse for negligence.
Knives are arranged around their circumference in such a way that the hopper feeding them presents an annular opening to the disk, say 7 ft.
In its original form, this consists of a long tube surrounded by an outer tube so arranged that cold water circulates in the annular space between the two.
Of a boss and circumferential annular channel, are placed face to face on a shaft, to which B is keyed, A being free (fig.
The lines of cardinal importance are (I) the rasceta or cross sulci, which isolate the hand from the forearm at the wrist, and which are the flexion folds between the looser forearm skin and that tied down to the fascia above the level of the anterior annular ligament.
As early as 1831 (during the annular eclipse of the sun) she had been her father's assistant in his observations.
From 1848 to 1878 it was but with few interruptions employed for observations of nebulae (see Nebula); and many previously unknown features in these objects were revealed by it, especially the similarity of "annular" and "planetary" nebulae, and the remarkable "spiral" configuration prevailing in many of the brighter nebulae.
The coral islands are generally of the form well known under the name of atoll, rising but slightly above sea-level, flat, and generally of annular form, enclosing a lagoon.
One of the expedients for inducing a state of fruitfulness in trees is the ringing of the branches or stem, that is, removing a narrow annular portion of the bark, by which means, it is said, the trees are not only rendered productive, but the quality of the fruit is at the same time improved.
The Kjellin furnace consists essentially of an annular trough, AA (fig.
To the legs is screwed a plate 00, which supports the lower side of the plate PP. This receives the ends of the screws SS by which the instrument is levelled, its annular portion being larger than the collar in 00, so that, until clamped by the screwed plate above it, the whole of the instrument except the legs can be moved horizontally in any direction to the extent of about in.
Below the piston of the upper cylinder is an annular space E (surrounding the common piston rod) with a capacity equal to the maximum displacement of the liftram, while the corresponding annular area C of the piston of the lower cylinder is just large enough when subjected to the working water pressure to enable the work of lifting the net load to be done and any friction to be overcome.
To work the lift, pressure-water is admitted to the annular space C above the lower of the two balance pistons (the space B above the upper one is always in communication with the pressure-water), and the combined pressure on the two pistons is sufficient to lift the cage, ram and load.
2) the ram A has an annular area so proportioned that when it is connected with the water in an elevated tank (usually placed somewhere in the roof of the building), the hydraulic pressure upon it just balances the weight of the ram and cage.
Within this is hung loosely a second tube of much smaller dimensions so as to leave an annular space between the two.
Should be converted economical method, but, as will be seen in the diagram, the quality of the boards will vary very much, some consisting almost entirely of sap-wood cut at a tangent to the annular rings such as a, b, c, whilst the centre boards contain the heartwood cut in the best way at right angles across the annual rings as d, e, f.
"Cup shake" is a natural splitting in the interior of the tree between two of the annular rings.
The wood is a light yellowish brown in colour, fine in grain and of even texture, the annular rings being marked by a darker line.
Ft.; it has a straight grain free from many knots; in colour it is of a rather deep yellow or brownish tint, with the hard portions of the annular rings marked in a darker red.
The wood is very hard, tough, with fine regular grain and close texture, the annular rings being distinct and the medullary rays well marked.
Its colour is light brown, sometimes with a greenish tint, with the annular rings of darker colour.
The wood is light brown or yellowish white, with annular rings not very distinct, often cross-grained and of uniformly coarse texture.
At Haibak there is a very perfect excavation called the Takht-iRustam (a general name for all incomprehensible constructions amongst the modern inhabitants of Afghan Turkestan), which consists of an annular ditch enclosing a platform, with a small house about 21 ft.
To add to the fairly uniform distribution of stars between two planes a gigantic cluster of an annular or spiral form, also lying between the planes and completely surrounding the sun.
In A there is a displacer (D) which is connected (by parts not shown) with the piston in such a manner that it moves down when the piston has moved up. The air-pressure is practically the same above and below D, for these spaces are in free communication with one another through the regenerator (E), which is an annular space stacked loosely with wire-gauze.
Deep is surrounded by an annular stone pavement about 7 ft.
When the eclipse is total, there is a real geometrical shadow - very small compared with the penumbra (for the apparent diameters of the sun and moon are nearly equal, but their distances are as 370: I); when the eclipse is annular, the shadow is all penumbra.