DIEGO. A very strong and heavy sword.
DIE ON THE FIN, To. An expression applied to whales, which when dying rise to the surface, after the final dive, with one side uppermost.
DIET. The regulated food for patients in sick-bays and hospitals.
DIFFERENCE. An important army term, meaning firstly the sum to be paid by officers when exchanging from the half to full pay; and, secondly, the price or difference in value of the several commissions.
DIFFERENCE OF LATITUDE. The distance between any two places on the same meridian, or the difference between the parallels of latitude of any two places expressed in miles of the equator.
DIFFERENCE OF LONGITUDE. The difference of any place from another eastward or westward, counted in degrees of the equator: that is, the difference between two places is an arc of the equator contained between their meridians, but measured in space on the parallel. Thus the difference of a degree of longitude in miles of the meridian would be—
| At | 20° | lat. | 56·4 | miles |
| " | 40 | " | 38·6 | " |
| " | 60 | " | 30·0 | " |
| " | 80 | " | 10·4 | " |
DIFFERENTIAL OBSERVATION. Taking the differences of right ascension and declination between a comet and a star, the position of which has been already determined.
DIFFICULTY. A word unknown to true salts.
DIGHT [from the Anglo-Saxon diht, arranging or disposing]. Now applied to dressing or preparing for muster; setting things in order.