Observations, number required; to procure calculation of.
Occultations, telescopes for.
Oil (olive) to refine (see "Grease").
Ointment.
Opera glass as a night glass; supplies a burning lens; and a lens to condense light.
Ophthalmia.
Organising an Expedition--Best size for party; servants' engagement; women.
Osborn, Captain Sherard, R.N.
Ostrich eggs, to carry.
Oswell, Mr. W. C.