Ottawa had many mills and manufacturing companies along the Ottawa River. One of the lesser known mill was located behind parliament hill near the famous Rideau Canal.
The following historical information was provided by University Of Ottawa and written by Mr. Weinberg.
"The stone foundation of the building with the tall smoke stack shown in the photograph below is still there to be admired along the bike path below Parliament Hill. The building was actually a Canadian classic and many views of the Parliament buildings from Major's Hill Park or from Hull show the mill in association with the Library of Parliament. There is a picture of it on the back of the four dollar bill of 1900. "Picturesque Canada", a book of engravings from 1882, includes a wonderful view of this mill. This ashlar foundation dates back to the 1870's during the great boom of the Ottawa lumber operations.
It may seem odd that permission would be granted to build a steam mill below Parliament Hill where, just a few years earlier, the greatest neo-gothic monument in North America, the Canadian House of Parliament was built. A smokey vulgar steam-powered lumber mill, noisily sawing wood and spewing sawdust was set right below our national parliament! The first Prime Minister Sir John A. MacDonald held that there should always be industry within view of Parliament Hill to reinforce the impression of the hard-working nature of Canadians. Was this symbolic consideration the basis for the permission given by the planners of the national capital to build the mill?
The earliest representation of the mill that I can find is on the "Bird's Eye View of the City of Ottawa" drawn by Herm. Brosius and published in 1876. In that year the lumber industry in Ottawa was in the midst of a depression so it is more likely the mill was built a few years before that. The mill is not shown on any of the river views drawn in the 1860's. In 1871 in Ottawa there were approximately 1,200 saws producing 250 million board feet of lumber annually and therefore, that year seems the most reasonable time to suppose it was constructed. When was it taken down? It is shown on a map of Ottawa of 1918 in the Ottawa room of the public library. It is definitely missing from a certain 1932 watercolour of the back of Parliament. I have not seen it in any photographs from after 1916 with the new Parliament buildings. Was it a casualty of the municipal beautification exercises which took place between the wars?
The mill was about 40 feet wide and 60 feet deep with a smoke stack that towered about 60 feet above river level. Photographs show the top half of the stack was lighter in colour than the bottom half. The steam boiler was certainly fueled by cuttings and wood waste from the industry. It was one of many steam mills in the Ottawa area. The first steam-powered sawmill in the Ottawa area was owned by J.C.Blasdell in 1849 on the Ottawa River near Rockcliffe. Andrew Leamy built a second at Leamy Lake in 1853. In 1868 there was a steam mill built on the Hull shore opposite the Parliament buildings for the Wright & Batson Co.
A more detailed photo shows a stacking yard to the right of the building defined by a curious polygonal pier at the extreme right corner and a triangular work area defined by booms floating on the river. There were two piles of something in this stacking area and there is some evidence that logs were pulled to the right side of the building for processing inside.
Half way between the mill and the locks is a wood frame utility building with five riverside windows floating freely on the river. If one carefully compares the position of this utility building with the eastern end of the Parliament building above, it will be seen to be in two quite different relative positions on the two different photographs available. The building would just float up or down during the spring flooding and always stay at river log level."