PROCEEDINGS OF SECTION A. 55 



It is estimated that the work could be completed in about one year 

 at an approximate cost of £2,000. 



There is perhaps no necessity to go into further details at present. 

 It would have been a far more serious and costly task for Australia, 

 in its remote and isolated position from the rest of the world, to improve 

 its longitudes if other countries, especially Canada, had not already, 

 at their own great expense, contributed the greater part of the work 

 required for that purpose. 



It is now left to us to carry out our part, and the scheme briefly 

 outlined above is our part. 



With the completion of this undertaking, the " longitude girdle " 

 around the globe would present five main subdivisions, namely : — 

 Greenwich-Madras, 

 Madras-Southport (Queensland), 

 Southport-Vancouver, 



Vancouver-Montreal, • 



Montreal-Greenwich. 



each subdivision fulfilling the essential conditions demanded for 

 modern determinations of fundamental longitudes, each carrying, 

 practically, the same weight and each gaining considerable strength 

 from all the others ; thus forming a harmonious system equally reliable 

 in all its parts, and making, especially Indian, Australian, and Canadian 

 Longitudes, with their Transpacific and Transatlantic connexions, 

 comparable and adjustable on a sound plan acceptable to all concerned. 



Another consideration which concerns more directly the Govern- 

 ment of the Commonwealth of Australia, bears on this matter. It is 

 the position of the Federal Observatory at Mt. Stromlo. 



One of the objects for which this Observatory was established is 

 that the meridian passing through it shall be the prime meridian of 

 Australia to which all the longitudes of the country shall be referred, 

 thus connecting the various surveys of the States to the same longi- 

 tude Datum. 



Obviously the first requirement in this case is to determine with 

 the greatest attainable accuracy the Longitude of the Mt. Stromlo 

 Observatory. 



A value of this longitude could be obtained very simply with 

 existing means, both by geodetic connexion with Sydney or by exchange 

 of clock signals between Mt. Stromlo and one of the State Observatories. 

 The resulting value, however, would be affected by the probable error 

 of the longitudes of these observatories increased by the error introduced 

 in making the connexion. A more acceptable plan would be to connect 

 Mt. Stromlo Observatory with Dr. Klotz's terminal point of Trans- 

 pacific Longitudes at Southport, Queensland, but this would give a 

 Value depending only on the Canadian chain. 



