Online Encyclopedia

treatise entitled Construction, usage et proprietes du quadrant nouveau de mathematiques, in which the instrument associated with his name is described. He died at Ornans in 1637. The instrument invented by Vernier is frequently called a nonius, particularly in See also:

Germany, after Pedro See also:

NUNEZ, PEDRO (PETRUS NoNlUS) (1492—1577)

Nunez (1492–1577), See also:

PROFESSOR (the Latin noun formed from the verb profiteri, to declare publicly, to acknowledge, profess)

professor of See also:

MATHEMATICS (Gr. /saBnµar1Kil, Sc. vOcvn or E7rlQTt'µn; from p iN.La, "learning" or "science ")

mathematics at the university of See also:

COIMBRA

Coimbra; but this is incorrect, as the contrivance described by the latter in his See also:

WORK

work De crepusculis (1542) is a different one, although the principle is practically the same. Nunez See also:

drew on the See also:

PLANE

plane of a quadrant 44 concentric arcs divided respectively into 89, 88, 46 equal parts; and if the See also:

ALIDADE (from the Arab.)

alidade did not coincide with one of the divisions on the See also:

PRINCIPAL

principal arc, which was divided into 90 parts, the number of degrees in a quadrant, it would fall more or less accurately on a See also:

DIVISION (from Lat. dividere, to break up into parts, separate)

division See also:

LINE

line of one of the See also:

AUXILIARY (from Lat. auxilium, help)

auxiliary arcs, from which the value of the measured See also:

ANGLE (from the Lat. angulus, a corner, a diminutive, of which the primitive form, angus, does not occur in Latin; cognate are the Lat. angere, to compress into a bend or to strangle, and the Gr. ayKOS, a bend; both connected with the Aryan root ank-, to

angle could be made out. This instrument was, however, very difficult to make, and was but little used. Vernier proposed to attach to a quadrant divided into See also:

HALF

half-degrees a movable sector of a length equal to 31 half-degrees, but divided into 30 equal parts, whereby single minutes could be read off by seeing which division line of the "sector" coincided with a division line of the quadrant. The See also:

IDEA (Gr. Ibia, connected with i&eiv, to see; cf. Lat. species from specere, to look at)

idea had been mentioned by See also:

CHRISTOPHER, SAINT (Christophorus, Christoferus)

Christopher Clavius (1537–1612) in his See also:

OPERA (Italian for " work ")

Opera malhematica, 1612 (ii. 5 and iii. to), but he did not propose to attach permanently an arc divided in this way to the alidade; this happy application of the principle at all events belongs to Vernier. The principle of the vernier is readily understood from the following See also:

account: Let AB (see fig.) be the normal See also:

scale, i.e. a scale graduated according to a See also:

standard of length, CD, a scale (placed in contact with AB for convenience) graduated so that to divisions equal 11 divisions of the scale AB, and EF a scale placed similarly and graduated so that to divisions equal 9 divisions of the scale AB.

Consider the See also:

COMBINATION (Lat. combinare, to combine)

combination AB and CD. Obviously each division C1 D a 7 8 O 9 10 1 I I I a 9 2 OIL E F of CD is th greater than the normal scale division. Let a represent a length to be measured, placed so that one end is at the zero of the normal scale, and the other end in contact with the end of the vernier CD marked to. It is noted that See also:

GRADUATION (see also GRADUATE)

graduation 4 of the vernier coincides with a division of the standard, and the determination of the excess of a over 3 scale divisions reduces to the difference of 7 divisions of the normal scale and 6 divisions of the vernier. This is .4, since each vernier division equals 1.1 scale division. Hence the scale See also:

READING

reading of the vernier which coincides with a graduation of the normal scale gives the decimal to be added to the normal scale reading. Now consider thq scales AB and EF, and let $ be the length to be measured; the scale EF being placed so that the zero end is in contact with an end of $. Obviously each division of EF is ,15th less than that of the normal scale. It is seen that division 6 of the vernier coincides with a normal scale division, and obviously the excess of fl over two normal scale divisions equals the difference between 6 normal scale divisions and 6 vernier divisions, i.e. 0.6. Thus again in this See also:

case the vernier reading which coincides with a scale reading gives the decimal to be added to the normal scale. The second type of vernier is that more commonly adopted, and its application to See also:

SPECIAL

special appliances is quite See also:

SIMPLE

simple.

For example, the normal scale to an See also:

ENGLISH

English See also:

BAROMETER (from Gr. (3apoc, pressure, and µETpov, measure)

barometer is graduated in TSths of an See also:

INCH (O. Eng. ynce from Lat. uncia, a twelfthpart; cf. " ounce," and see As)

inch. The vernier is such that 24 divisions of the normal scale equal 25 of the vernier; each of the latter therefore is •002 or• .azth inch less than the normal division. In the scientific barometer, the normal scale is graduated in milli-metres, and the vernier so that 20 scale divisions equal 19 mm. This combination reads to 0.05 mm.

End of Article: VERNIER, PIERRE (c. 1580–1637)

Additional information and Comments

There are no comments yet for this article.

» Add information or comments to this article.

Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML.

Site content, images, and layout Copyright © 2006 - Net Industries, worldwide.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.

Links to articles and home page are always encouraged.

[back]
VERNEY

[next]
VERNIS MARTIN