Section III., 1892. [ 33 ] Trans. Rot. Soc. Canada. 



V. — Memo, as to préparai ions for the proposed iransatlantic longitude determinations : 



Greenwich — Waterville — Canso — Montreal, 



By Prof, d? H. McLeod, Ma. E., Superintendeut McGill College Observatory, Montreal. 



(Read May, 1891.) 



The general outline of work has been settled upon as follows : — The cable terminii, 

 "Waterville, in Ireland, and Canso, in Nova Scotia, will be occupied as Astronomical 

 Stations, thus dividing the work into three sections. Greenwich-Waterville, through 

 the land lines and Channel Cable ; Waterville-Canso through one of the Commercial 

 Company's Cables ; Canso-Moutreal through the Canadian Pacific Railway Telegraph line. 

 An independent series of signals between G-reenwich and Montreal, by automatic repe- 

 tition of the signals between the land lines and the cable is also contemplated. 



Mr. Turner, Chief Assistant to the Astronomer Royal, is now making a preliminary 

 visit to "Waterville for the purpose of selecting a site for the transit instrument and build- 

 ing a pier, and will take advantage of his visit to make some trial signals through the 

 cable. I shall visit Canso in a few days with the same object in view. These prélim- 

 inaires being arranged, it is proposed to divide the work into three parts. The first part 

 to be carried out during the mouth of August next without interchange of observers, and 

 to be largely of the nature of an experimental programme. The primary object will be 

 to gain experience in the management of the cable. It is desired to obtain three full 

 nights of observations ^n this series, and it will probably occupy three weeks. 



The second part of the programme will be commenced in April or early in May, 1892. 

 There will be four observers, two Canadian and two English, and the scheme of work will 

 probably be as follows, naming the observers B, C, D and E : 



Montreal. Canso. " Waterville. Greenwich. "'^ob^e^rvaUona.'*'^ 



B C D E 3 



B E D 3 



The observers C and D then cross the Atlantic. 



B D C E 3 



D B E C 3 



This should occupy from 10 to 12 weeks, or until, say, July 15th. The third part of 

 the work should then be commenced about August 15th, and be carried out in a precisely 

 similar manner, the Canadian observer who has crossed the Atlantic beginning work in 

 "Waterville and the English observer in Canso. The second and third portions of the 

 work will therefore afford two complete and independent determinations of longitude, 

 and will be so placed in the spring and autumn of the year, as to fall as far apart as 



Sec. III., 1&92. 5. 



