90 PRACTICAL ASTRONOMY IN TASMANIA. 



that the Harkness position and the present Observatory 

 are situated lelatively thus: — 



'Present Hobart Observatory relative to the transit of 

 Venus (transit iustrumeut) pier. 



Lat. 3.61" S., Lon. 0.051 s. W. 

 The present (1902) revised position of our Observatory is 

 therefore 



Lat. 42° 53' 28.2" S., Lou. 9h. 49m. 19.54 s. E., 

 whereas in recent years the adopted values have been 

 Lat. 42° 53''2S.3" S., Lon. 9h. 49min. 19.76 s. E 



II. 



The Uses and Desirabilities of Practical Astronomy 



IN such a Community as Ours. 



I will now repeat and correct my remarks of two months 

 ago. I said then that the keeping of time was so necessary 

 for an island State such as Tasmania that it was imperative 

 to know the time as accurately as possible. This I 

 still believe. I also said (in the deputation of this Society 

 to the Premier) that a first-class Observatory kept time to 

 1/100 of a second. This I said in ignorance. It is not so. 

 Of this, more directly. 



It is imperative to know the time as accurately as pos- 

 sible for tnis reason : Mariners depend ujDon the time for 

 their position. I could say how they know their position 

 North or South of the Equator by direct observations with 

 the sextant, but this would occupy too much time, and I 

 will only speak of how they determine their position East 

 or West of some ascertained spot. They do this by means of 

 their chronometers and sextant observations. If ocean 

 mariners had a say in colonial politics, they would un- 

 doubtedly say, "Please give us time correctly; chronometers 

 are excellent in their way, but their indications depend ulti- 

 mately on observations of the stars, and these observations 

 can only be properly carried out at fixed Observatories.'' 



The rate of chronometers at sea is of the utmost im- 

 portance, not only to mariners, but to the general public 

 who travel by sea, for an error in the rate of one second in 

 two days may mean an error of ten seconds in 20 days, and 

 an error of 10s. in the chronometer may mean nearly three 

 statute miles' error in position. 



Is Tasmania a place where time should be kept ac- 

 curately? I have no hesitation in answering ''Yes." Tas- 

 mania has a port where steamers from South Africa call on 

 their way to distant ports ; other steamers call which are 

 destined for a long voyage (say, starting from Sydney), af- 

 ter staying for a time at Hobart. It is absolutely necessary 



