37 

 ITINERARY OF THE EXCURSION. 



Annotated guide. — (Montreal to Ormsby Junction.) 



Miles and 

 Kilometres. 



o.m. Montreal (Bonaventure station, Grand 



o.km. Trunk railway), with a population of 592,000, is 

 the largest city and the commercial metropolis 

 of Canada. It is situated on the south side of 

 an island of the same name at the confluence of 

 the Ottawa and St. Lawrence rivers. It is at 

 the head of ocean navigation and at the com- 

 mencement of lake and river navigation. The 

 city has been built about the base of Mount 

 Royal, an intrusive mass of Devonian or post- 

 Devonian age, composed principally of essex- 

 ite and nepheline syenite, which rises to a 

 height of 763 feet (232-56 m.) above the sea or 

 742 feet (226-16 m.) above the standard low 

 water of the river. On its sides may be seen 

 terraces and beaches, the records of post- 

 glacial subsidence, the highest shore line having 

 an altitude of 568 feet (173-1 m.) above the sea. 

 St. Catherine and Sherbrooke streets respective- 

 ly follow two of the most important terraces. 

 The city is underlain by rocks of the Trenton 

 group, which furnish the grey limestone so 

 much in use locally for building purposes. 

 Utica shale outcrops at Verdun and Point St. 

 Charles and underlies the harbour and the south 

 end of St. Helen's island. Masses of limestone 

 included in the igneous breccia of St. Helen's 

 island are of Lower Helderberg (Upper Silurian) 

 and Oriskany (Lower Devonian) ages. These 

 occurrences are of interest as evidences of the 

 extension of the Upper Silurian and Lower 

 Devonian seas as far inland as Montreal. The 

 Trenton is usually credited with a thickness of 

 600 feet (183 m.) and the Utica 300 feet (92 m.) 

 in the region surrounding Montreal. 



Leaving Montreal the railway runs to the 

 southwest following a natural depression, which 

 extends nearly to the shores of Lake St. Louis, 



