Renseignements généraux

Nº de série

S/O

Nº de partie

2

Nombre total de parties

2

Ou

S/O

Brevets

S/O

Description générale

Wood, leather, brass.

Dimensions

Remarque : Cette information reflète la taille générale pour l’entreposage et ne représente pas nécessairement les véritables dimensions de l’objet.

Longueur

24,7 cm

Largeur

26,0 cm

Hauteur

17,2 cm

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Exploration et levé

Catégorie

Mesure-direction

Sous-catégorie

S/O

Fabricant

Ou

White

Pays

Écosse

État/province

Inconnu

Ville

Glasgow

Contexte

Pays

Inconnu

État/province

Inconnu

Période

Inconnu

Canada

Inconnu

Fonction

Inconnu

Technique

Inconnu

Notes sur la région

Inconnu

Détails

Marques

Tag attached to wooden box reads: 'Article No 148/ Azimuth Mirror/ Kelvin # 5660/ Hydrographic/ Condition - good' White sticker with red border adhered to box reads: 'AZIMUTH MIRROR H.S.No./ Desc . Brass about 7"/ Maker; Kelvin No.5660/ Condition; Fair, Centre pins missing/ Bubble evaporated' Instructions adhered to the inside of the box door reads: 'INSTRUCTIONS FOR THE USE OF LORD KELVIN'S AZIMUTH MIRROR.// BEARINGS can be taken with this instrument in two/ ways. (1) By looking direct at the object over the top of/ the prism. The degrees of the card reflected in the prism/ are then seen close below the object ; (2) By looking through/ the lens at the degree of the card. The first method is applicable/ to objects on the horizon, and is more particularly useful/ for taking bearings of distant landmarks which are too indis-/ tinct to be seen when reflected in the prism. The second/ method may be used either for taking bearings of objects/ on the horizon or for taking bearings of the sun, moon, or/ stars.// For taking bearings by the first method the prism is kept/ turned (arrow-head down) with its mounting stopper against/ the framework. The observer turns the instrument round/ its vertical axis till the prism and lens are fairly opposite/ to the object, and places his eye so as to see the object over/ the prism and reads the bearing of the object from the com-/ pass card as seen reflected in the prism.// For taking bearings by the second method the observer/ looks through the lens at the degree divisions of the com-/ pass card and turns the prism (arrow-head up) round its/ horizontal axis till he brings the image of/ the object to fall/ on the card. He then reads directly on the card the com-/ pass bearing of the object.// The pointer is used merely as an aid in directing the/ instrument towards the object, but the bearing is read directly/ from the object as seen on the compass card. It is not/ necessary the pointer should be pointing exactly towards/ the object unless the altitude be very high For objects/ from horizon up to 38 [symbol for degrees] of altitude the error on the bearing/ would be less than half a degree, even if the pointer were/ pointing 4 [symbol for degrees]/ away from the object.// Makers - KELVIN & JAMES WHITE, Ltd.. 16 to 20 Cambridge Street, Glasgow.'

Manque

S/O

Fini

Inconnu

Décoration

S/O