C# Edge Browser Control

Posted onby
Vietnam War-era P-38 can opener. U.S. one cent coin shown for size comparison.
  1. Wpf Edge Browser Control
  2. C-diff

USB-C is the latest physical format for USB connections on devices, replacing USB-A. It’s much, much faster, has more powerful charging capabilities, can handle UHD video connections with ease.

The P-38, developed in 1942,[1] is a small can opener that was issued in the canned field rations of the United States Armed Forces from World War II to the 1980s. Originally designed for and distributed in the K-ration, it was later included in the C-ration. As of 2020, it is still in production and sold on a worldwide market.[2]

This is a reader-friendly overview of Vitamin C. For more details, see our health professional fact sheet on Vitamin C. For information on Vitamin C and COVID-19, see the NIH COVID-19 Treatment Guidelines on Vitamin C. Vitamin C, also known as ascorbic acid, is a water-soluble nutrient found in some. The copyright symbol, or copyright sign, designated by (a circled capital letter 'C'), is the symbol used in copyright notices for works other than sound recordings.


P-38 can opener measured by digital calipers. It is 38.31 millimetres (1.508 in).

The P-38 is known as a 'John Wayne' by the United States Marine Corps, because of its toughness and dependability.[3][unreliable source?][citation needed] The can opener is pocket-sized, approximately 1.5 inches (38 mm) long, and consists of a short metal blade that serves as a handle, with a small, hinged metal tooth that folds out to pierce the can lid.

A notch just under the hinge point keeps the opener hooked around the rim of the can as the device is 'walked' around to cut the lid out. A larger version called the P-51 is somewhat easier to operate. The handle portion can also double as a makeshift flat-blade screwdriver, with limited ability because of the rather soft sheet metal used.

Official military designations for the P-38 include 'US ARMY POCKET CAN OPENER' and 'OPENER, CAN, HAND, FOLDING, TYPE I'. As with some other military terms, e.g., 'jeep', the origin of the term is not known with certainty; the P-38 opener coincidentally shares a designation with the Lockheed P-38 Lightning fighter plane, which could allude to its fast performance, additionally the P-51 can opener also has an aircraft namesake in the North American P-51 Mustang.[1]

One technical explanation for the origin of the name is that the P-38 is approximately 38 millimetres long. This explanation also holds for the P-51, which measures approximately 51 mm (2.0 in) in length. However, use of the metric system in the US was not widespread at this point, and United States Army sources indicate that the origin of the name is rooted in the 38 punctures around the circumference of a C-ration can required for opening.[1]

Size comparison of P-51 and P-38 openers

P-38s are no longer used for individual rations by the United States Armed Forces, as canned C-rations were replaced by MRE rations in the 1980s, packed in plastic pouches. The larger P-51s are included with United States military 'Tray Rations' (canned bulk meals). They are also still seen in disaster recovery efforts and have been handed out alongside canned food by rescue organizations, both in America and abroad in Afghanistan.

The original U.S.-contract P-38 can openers were manufactured by J.W. Speaker Corporation of Germantown, Wisconsin[4] (stamped 'Speaker USA') and by Washburn Corporation (marked 'US Androck'); they were later made by Mallin Shelby Hardware inc (defunct 1973) of Shelby, Ohio and were variously stamped 'US Mallin Shelby O.' or 'U.S. Shelby Co.'


The P-38 is cheaper to manufacture than a standard can opener, and is smaller and lighter to carry. The device can be easily attached to a keychain or dog tag chain using the small punched hole.


A U.S. Army C-ration with can opener, Da Nang, Vietnam, c 1966–1967.

The P-38 is easily used. First, the cutting point is pivoted to its 95-degree position,[5] from its stowed, folded position. Then, for a right-handed user, the P-38 is held in the right hand by the flat long section, with the cutting point pointing downward and away from the user, while also hooking the edge of the can through the circular notch located on the flat long section next to the cutting edge. The can is held in the left hand, and the right hand is rotated slightly clockwise, causing the can lid to be punctured.

The can is then rotated counter-clockwise in the left hand, while the right hand rotates alternatively slightly counter-clockwise and slightly clockwise, until the can has been rotated nearly 360 degrees and the lid is nearly free. The lid of the now opened can is lifted, most often with the P-38 cutting edge, and the P-38 is wiped clean, and the cutting point is rotated back to its stowed, folded position. The P-38 is then returned to its stored location, whether that is dangling on a dog tag chain around one's neck, or in one's pocket if the P-38 is attached to a key ring.

Left-handed users simply hold the P-38 in their left hand, with the cutting point aimed towards themselves, while holding the can to be opened in their right hand, while also reversing the sense of the cutting hand movements just described. By tradition, 38 cuts as just described were supposedly required to open a can of C-Rations.

A left-handed user is at a slight disadvantage in that the tip of the thumb (instead of the lateral flank of the distal index finger) must apply the combined travel & twist forces. Righties' thumbs take only the twist force.

Similar devices[edit]

A standard issue 'FRED' can opener of the Australian Defence Force.

A similar device that incorporates a small spoon at one end and a bottle opener at the other is currently employed by the Australian Defence Force and New Zealand Army in its ration kits. The Field Ration Eating Device is known by the acronym 'FRED'. It is also known widely in its derogative term, the 'Fucking Ridiculous Eating Device'.[6][7]

Another similar device was included with British Army 'Operational Ration Pack, General Purpose' 24-hour ration pack and 'Compo' Composite (14 man) Ration pack rations. At one stage they were manufactured by W.P. Warren Engineering Co. Ltd, Birmingham, England. The instructions printed on the miniature greaseproof paper bag they were supplied in read:

Place opener on the can with rim of can inside the slot. Hold between thumb and forefinger and twist forward to puncture. Repeat motion until can is open.

It takes approximately 38 twists to fully open a C-ration can. Their design is similar, but not identical, to the P-38 and P-51 can openers.

The Swedish army also employed a similar variant of this opener. Its official designation is M7481-021000 Konservbrytare Mini which was distributed with the notorious 'Golden Cans' (Swedish field rations were packaged in metallic tins with a golden hue). In 1924, a similar device was featured in Popular Mechanics, with no mention of a military provenance.[8]

An opener similar to the P-38, but with a non-folding blade, was popular in Poland for years. It can still be found in shops as well as the butterfly-type openers.

See also[edit]


  1. ^ abcFoster, Renita (2009-08-11). 'The best Army invention ever'. www.army.mil. US Army. Retrieved 2014-12-19.CS1 maint: discouraged parameter (link)
  2. ^'Buy P38 or P51 Can Opener at Army Surplus World Army Surplus World'. www.armysurplusworld.com. Retrieved 2020-01-04.
  3. ^'P38 Can Opener'. Retrieved 16 June 2015.CS1 maint: discouraged parameter (link)
  4. ^'Small Wonder'. Milwaukee Magazine. Retrieved 29 November 2016.CS1 maint: discouraged parameter (link)
  5. ^'MILITARY SPECIFICATIONS AND DRAWINGS FOR P-38 AND P-51 CAN OPENERS'. www.georgia-outfitters.com.
  6. ^Hardiman, Graeme. 'The Malayan Emergency. 2RAR 1956/57'. Digger History: an unofficial history of the Australian & New Zealand Armed Forces. Retrieved 2007-11-05.CS1 maint: discouraged parameter (link)
  7. ^'Australian Ration pack Contents'. Ration Pack. Australian Defence News & Opinion. 2007. Archived from the original on 2007-10-12. Retrieved 2007-11-05.CS1 maint: discouraged parameter (link)
  8. ^'Women's Workshop'. Popular Mechanics. April 1924. Retrieved 2016-05-26.CS1 maint: discouraged parameter (link)

External links[edit]

Retrieved from 'https://en.wikipedia.org/w/index.php?title=P-38_can_opener&oldid=1008744471'
Middle C Play

Wpf Edge Browser Control

C or Do is the first note of the C majorscale, the third note of the A minor scale (the relative minor of C major), and the fourth note (F, A, B, C) of the Guidonian hand, commonly pitched around 261.63 Hz. The actual frequency has depended on historical pitch standards, and for transposing instruments a distinction is made between written and sounding or concert pitch.

In English the term Do is used interchangeably with C only by adherents of fixed-Do solfège; in the movable Do system Do refers to the tonic of the prevailing key.




Historically, concert pitch has varied. For an instrument in equal temperament tuned to the A440 pitch standard widely adopted in 1939, middle C has a frequency around 261.63 Hz (for other notes see piano key frequencies). Scientific pitch was originally proposed in 1713 by French physicist Joseph Sauveur and based on the numerically convenient frequency of 256 Hz for middle C, all C's being powers of two. After the A440 pitch standard was adopted by musicians, the Acoustical Society of America published new frequency tables for scientific use. A movement to restore the older A435 standard has used the banners 'Verdi tuning', 'philosophical pitch' or the easily confused scientific pitch.

Octave nomenclature[edit]


Middle C[edit]

Middle C (the fourth C key from left on a standard 88-key piano keyboard) is designated C4 in scientific pitch notation, and c′ in Helmholtz pitch notation; it is note number 60 in MIDI notation.[1]

While the expression Middle C is generally clear across instruments and clefs, some musicians naturally use the term to refer to the C note in the middle of their specific instrument's range. C4 may be called Low C by someone playing a Western concert flute, which has a higher and narrower playing range than the piano, while C5 (523.251 Hz) would be Middle C. This technically inaccurate practice has led some pedagogues to encourage standardizing on C4 as the definitive Middle C in instructional materials across all instruments.[2]

On the Grand Staff, middle-C is notated with a ledger line above the top line of the bass staff or below the bottom line of the treble staff. Alternatively, it is written on the centre line of a staff using the alto clef, or on the fourth line from the bottom, or the second line from the top, of staves using the tenor clef.

Other octaves[edit]

In vocal music, the term High C (sometimes less ambiguously called Top C[3]) can refer to either the soprano's C6 (1046.502 Hz; c′′′ in Helmholtz notation) or the tenor's C5; both are written as the C two ledger lines above the treble clef but the tenor voice sings an octave lower. The term Low C is sometimes used in vocal music to refer to C2 because this is considered the divide between true basses and bass-baritones: a basso can sing this note easily, whereas other male voices, including bass-baritones, typically cannot.

Tenor C is an organ builder's term for small C or C3 (130.813 Hz), the note one octave below Middle C. In stoplists it usually means that a rank is not full compass, omitting the bottom octave.

Designation by octave[edit]

Scientific designationHelmholtz designationOctave nameFrequency (Hz)Other namesAudio
C−1C͵͵͵ or ͵͵͵C or CCCCOctocontra8.176Play
C0C͵͵ or ͵͵C or CCCSubcontra16.352Play
C1C͵ or ͵C or CCContra32.703Play
C2CGreat65.406Low C, cello C, 8' C (see organ pipe length)Play
C3cSmall130.8134' C or tenor C (organ), viola CPlay
C4c′One-lined261.626Middle CPlay
C5c′′Two-lined523.251Treble C, high C (written an octave higher for tenor voices)[4]Play
C6c′′′Three-lined1046.502High C (soprano)Play
C7c′′′′Four-lined2093.005Double high C[citation needed]Play
C8c′′′′′Five-lined4186.009Eighth octave C, triple high CPlay
C9c′′′′′′Six-lined8372.018Quadruple high CPlay
C10c′′′′′′′Seven-lined16744.036Quintuple high CPlay

Note that for a classical piano and musical theory, the middle C is usually labelled as C4; However, in the MIDI standard definition (like the one used in Apple's GarageBand), this middle C (261.626 Hz) is labelled C3. In practice, a MIDI software can label middle C (261.626 Hz) as C3-C5, which can cause confusion, especially for beginners.

Graphic presentation[edit]

Middle C in four clefs
Position of Middle C on a standard 88-key keyboard


Common scales beginning on C[edit]

  • C Major: C D E F G A B C
  • C Natural Minor: C D E F G A B C
  • C Harmonic Minor: C D E F G A B C
  • C Melodic Minor Ascending: C D E F G A B C
  • C Melodic Minor Descending: C B A G F E D C

Diatonic scales[edit]

  • C Ionian: C D E F G A B C
  • C Dorian: C D E F G A B C
  • C Phrygian: C D E F G A B C
  • C Lydian: C D E F G A B C
  • C Mixolydian: C D E F G A B C
  • C Aeolian: C D E F G A B C
  • C Locrian: C D E F G A B C

Jazz melodic minor[edit]

  • C Ascending Melodic Minor: C D E F G A B C
  • C Dorian ♭2: C D E F G A B C
  • C Lydian Augmented: C D E F G A B C
  • C Lydian Dominant: C D E F G A B C
  • C Mixolydian ♭6: C D E F G A B C
  • C Locrian ♮2: C D E F G A B C
  • C Altered: C D E F G A B C

See also[edit]


  1. ^'MIDI Note/Key Number Chart', computermusicresource.com
  2. ^Large, John (February 1981). 'Theory in Practice: Building a Firm Foundation'. Music Educators Journal. 32: 30–35.
  3. ^Harold C. Schonberg (November 4, 1979). 'Birgit Nilsson – The Return of a Super-Soprano'. The New York Times.
  4. ^'The Note That Makes Us Weep' by Daniel J. Wakin, The New York Times, September 9, 2007
Retrieved from 'https://en.wikipedia.org/w/index.php?title=C_(musical_note)&oldid=1013628972'