Jacobsstaff

*I. Ordinary Language: 1. A pilgrim's staff, from the pilgrimages made to the Shrine of St. James (Lat. Jacobus ) at Compos tell a in Spain. "In his hand a Jacob's- staff , to stay His weary limbs upon." Spenser: F. Q., I. vi. 35. 2. A staff containing a concealed dagger. II. Surveying: 1. An instrument for taking altitudes, having a bra circle divided into four equal parts by two diametric lines. At each extremity is a perpendic ular riglet over the lines, with a hole below each slit for discovering objects. The cro is mounted on a staff. A cro -staff. 2. An instrument used to measure distances and heights. It has a square rod, with a cro or cursor, which has a set screw to keep it in position on the rod when required. The rod is three or four feet in length, and divided into four or five equal parts. The cursor has a square socket and slips on the staff. The instrument is mounted on a tripod when in use, the cursor being in the plane of the horizon when measuring distances, and vertical to it when measuring heights. 3. A straight rod shod with iron, and with a socket-joint and pintle at the summit for supporting a surveyor's circumferentor. Jacob's-stone, s. A stone fabulously said to be that on which Jacob rested his head at Luz, which was used as the coronation-stone of the kings of Scotland at Scone, in Perth shire, and was thence transferred by Edward I. to Westminster, where it still remains, inclosed in the coronation-chair. Jā'-cob (2), s. [From Jacob, its discoverer.] Anat .: (See etym. and compound.) Jacob's-membrane, s . Anat.: The columnar layer, or layer of rods or cones, constituting the seventh layer covering the retina of the eye. ( Quain .) Jắc-ô-bê-ạn, Jă-cô-bě-ạn, Jă-cô-bi-an, adj . [Lat. Jacob ( us )=James; English suff. -ean, -ian.] Arch .: A term sometimes applied to the style of architecture prevailing during the later years of the reign of Elizabeth and that of James I. It differs from the Elizabeth an or Tudor style, in having a greater admixture of Italian, greatly owing to the influence of the Italian architect Palladio. IMG:content-0094.jpg:[blocks in formation] jade