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

24,1 cm

Largeur

22,7 cm

Hauteur

22,8 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 149/ Azimuth Mirror/ Kelvin # 8379/ Hydrographic/ Condition - good' White sticker with red border adhered to box reads: 'AZIMUTH MIRROR H.S.No/ Desc . About 8" Complete/ Maker; Kelvin No.8379/ Condition: Good' 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/ divisions of the compass card, and at the image of/ the object in the prism which is seen on the proper/ 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 indistinct 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 bear-/ ings 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 compass 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 compass 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 compass 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 point-/ ing 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