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The diaphragm is in form like an inverted bowl
It forms the floor of the thorax (chest) and the roof of the abdomen. It is attached by a strong tendon to the spinal column behind, and to the walls of the thorax at its lowest part, which is below the ribs. In front its attachment is to the cartilage at the pit of the stomach. It also connects with the transverse abdominal muscle. The diaphragm being convex, in inspiration the contraction of its fibres flattens it downward and presses down the organs in the abdomen, thus increasing the depth of the thorax. Expiration depends wholly on other muscles.
Figure shows the limit of full expiration and inspiration of the male, side view
Section of the head and throat locating the organs of speech and song, including the upper resonators
The important maxillary sinus cannot well be shown. It is found within the maxillary bone (cheek bone). The inner end of the line marked Nasal cavity locates it.
Abraham Lincoln
Abraham Lincoln
The Early House of Abraham Lincoln
The vignette of Lincoln's early home on Goose-Nest Prairie, near Farmington, Ill., was built by Lincoln and his father in 1831.
Alexander H. Stephens
Alexander H. Stephens
Edwin M. Stanton
Edwin M. Stanton
Lyman Trumbull
Lyman Trumbull
The Fight Between The Monitor And The Merrimac
But the death of the Merrimac was to follow close upon her birth; she was the portent of a few weeks only. For, during a short time past, there had been also rapidly building in a Connecticut yard the Northern marvel, the famous Monitor. When the ingenious Swede, John Ericsson, proposed his scheme for an impregnable floating battery, his hearers were divided between distrust and hope; but fortunately the President's favorable opinion secured the trial of the experiment. The work was zealously pushed, and the artisans actually went to sea with the craft in order to finish her as she made her voyage southward. It was well that such haste was made, for she came into Hampton Roads actually by the light of the burning Congress. On the next day, being Sunday, March 9, the Southern monster again steamed forth, intending this time to make the Minnesota her prey; but a little boat, that looked like a "cheese-box" afloat, pushed forward to interfere with this plan. Then occurred a duel which, in the annals of naval science, ranks as the most important engagement which ever took place. It did not actually result in the destruction of the Merrimac then and there, for, though much battered, she was able to make her way back to the friendly shelter of the Norfolk yard. But she was more than neutralized; it was evident that the Monitor was the better craft of the two, and that in a combat à outrance she would win. The significance of this day's work on the waters of Virginia cannot be exaggerated. By the armor-clad Merrimac and the Monitor there was accomplished in the course of an hour a revolution which differentiated the naval warfare of the past from that of the future by a chasm as great as that which separated the ancient Greek trireme from the flagship of Lord Nelson.
Type of Magneto Telephone
Conversion from Vibration to Voice Currents. The figure illustrates a simple machine adapted to translate motion of a diaphragm into an alternating electrical current. The device is merely one form of magneto telephone chosen to illustrate the point of immediate conversion. 1 is a diaphragm adapted to vibrate in response to the sounds reaching it. 2 is a permanent magnet and 3 is its armature. The armature is in contact with one pole of the permanent magnet and nearly in contact with the other. The effort of the armature to touch the pole it nearly touches places the diaphragm under tension. The free arm of the magnet is surrounded by a coil 4, whose ends extend to form the line.
Polarized Ringer
If an electromagnet, a permanent magnet, and a pivoted armature be related to a pair of gongs as shown , a polarized ringer results. It should be noted that a permanent magnet has both its poles presented (though one of the poles is not actually attached) to two parts of the iron of the electro-magnet. The result is that the ends of the armature are of south polarity and those of the core are of north polarity. All the markings relate to the polarity produced by the permanent magnet. If, now, a current flow in the ringer winding from plus to minus, obviously the right-hand pole will be additively magnetized, the current tending to produce north magnetism there; also the left-hand pole will be subtractively magnetized, the current tending to produce south magnetism there. If the current be of a certain strength, relative to the certain ringer under study, magnetism in the left pole will be neutralized and that in the right pole doubled. Hence the armature will be attracted more by the right pole than by the left and will strike the right-hand gong. A reversal of current produces an opposite action, the left-hand gong being struck. The current ceasing, the armature remains where last thrown.