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In search of spirals in my ear

By snurfson / Posted on 07 December 2010

Description: In this figure are shown the winding passages of the ear (the labyrinth of the ear). The middle part of it (v) is the vestibule. From this go out on the upper side the semi-circular canals (x,y,z) and on the lower side of the passages of the cochlea (k). The opening into the vestibule (o) is covered by the second drum. Another opening (r) is also covered by a membrane or drum. The cochlea (k) is so called because it is shaped like a snail’s shell.

Image of cochlea

Source: Hooker, Worthington First Book in Physiology For the Use of Schools and Families (New York: Sheldon and Company, 1867) 174
Some Keywords: hearing, “ear passages”, “labyrinth of the ear”, cochlea, “semi-circular canals”, vestibule.

Vertical section of the shell of a species helix

Some Keywords: snail shell, helix shell, snail shell mouth, shell apex, columella, label snail shell parts.

A cross section of the ear

Description: Cross-section of the external and internal ear. a, b, and c: External ear. d: Entrance to the tube of the ear (f). g: Drum of the ear. h: Cavity beyond the drum where the chain of bones is, the bones being left out that the arrangement of the apparatus may be more clear to you. k: Tube which comes from the back part of the throat to this cavity. If you shut your mouth and close the nostrils with your fingers, and then force the air strongly from your chest into the mouth, you can feel the air pass through this tube into the ear where the little bones are. l: is the vestibule of the labyrinth. m: Semi-circular canals. n: Cochlea. o: Trunk of the nerve of hearing as it goes to branch out in the labyrinth. e: Bone in which the labyrinth is enclosed.
Source: Hooker, Worthington First Book in Physiology For the Use of Schools and Families (New York: Sheldon and Company, 1867) 175
Some Keywords: ear, hearing, “auditory canal”

Spiral

Description: An illustration showing how to construct a spiral with compasses and four centers. “Given the pitch of the spiral, construct a square about the center, with the four sides together equal to the pitch. Prolong the sides in one direction as shown by the figure, the corners are the centers for each arc of the external angles.”
Source: Albert A. Hopkins Scientific America: Handy Book Of Facts And Formulas (New York: Munn & Co., Inc., 1918) 39
Some Keywords: geometric construction, construct, geometry, analytic geometry, analytical, spiral, spirals

Drawing Equiangular or Logarithmic Spiral

Description: “If B and C are points in the spiral and the ratio of AC to AB be given, the intermediate point D may be obtained by describing a semicircle on BC as a diameter and erecting a perpendicular at A.” —Anthony, 1904
Source: Anthony, Gardner C. Elements of Mechanical Drawing (Boston: D. C. Heath & Co., 1904) 103
Some Keywords: Drawing Equiangular or Logarithmic Spiral, Equiangular Spiral, Log Spiral, Logarithmic Spiral, spiral, spirals

 

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