GEOGRAPHICAL LATITUDE. 756 



Be that as it may, this iusfcriiment must be recognized as one of the 

 most important aids to the early development of geography, and, 

 whether borrowed or invented by the Greeks, they deserve the credit 

 of having made the best use of it. In all probability the number of 

 l)laees whose latitude was determined by its use was exceedingly 

 limited,' as the geographers employed other means also for attaining 

 the same end. The rising and setting of certain fixed stars served as 

 one basis for calculating the latitude of places, while even untrust- 

 worthy data as to climate, wind, color of inhabitants, varieties of 

 animals, vegetable products, etc., were used to supply the lack of better 

 kinds of information. The ancients were right in considering the 

 length of the longest day an important factor in determining latitude, 

 and Hipparchus is said to have calculated what it should be for each 

 degree.^ However, the want of accurate time-pieces rendered it im- 

 possible to make exact observations. As to the instruments em- 

 ployed for astronomical observations we know almost nothing. Hip- 

 parchus, who was an ardent advocate of using the results of astronom- 

 ical observation for geographical purposes, does not mention by name 

 a single instrument which he employed, nor does he use even the generic 

 term instrument.^ Eratosthenes used the hollow gnomon (mentioned 

 • above) to determine the latitude of Alexandria,* and at his request the 

 king ordered to be made and placed on the roof of the museum the 

 famous armillary spheres, with which he determined the declination of 

 the Ecliptic to within six minutes of arc, a praiseworthy exactness for 

 that age."* To this may be added the known fact of Ptolemy's use of 

 the astrolabe at Ehodes*' and the invention of the sun-dial by Anaxi- 

 mander." With such simple means were the beginnings of the science 

 of geography made. 



Application. — It is difficult for us to realize the length of time re. 

 quired to make such small- advances as have been indicated, but the 

 history of other branches of science is parallel. The inertia to be over- 

 come in advancing from utter ignorance of a subject to the commence- 

 ment of real knowledge, and founding the principles on which investi- 

 gation should be carried on, is immense. Knowledge does not spring 

 into being, Minerva-like, completely developed, but resembles much 

 more the insignificant acorn, which, slowly growing and battling with 

 the elements, becomes in the course of time the mighty oak. Ages may 

 l)ass in the almost unheeded dreaming and theorizing of philosophers 



' Peschel, Gesch. d. Erdkunde, 44, '15. 

 ^ Spreuger, Ausland, ItitiT, p. 1045. 



^Delarnbre, Asrrouomie ancienne, i, 1:59. At the same time lie (iiiuks Ilippaichus 

 was possibly the iuveutor of the astrolabe, i, 184. 

 * Ibid, 1,221. 



''Miidler, Gesch. d. Himiiielskiiiide, i. 57. 

 ''Delambre, Astron. ancieime, I, lrt4, 

 'Manuert, i. 11, 



