John Thow is thought to have made bagpipes as early as 1853. He died in 1879 and his son David continued making bagpipes until his death in 1916. David's sons, John and George continued the business as Thow Brothers. John died in 1923 and George died in 1940. Thow Brothers continued to make bagpipes until 1952. The firm was apparently run by George's daughter Marjorie Thow and perhaps a brother, George W R Thow. 
thowviolin1
According to Jeanne Campbell, John Thow was listed as a musical instrument maker begining in 1853. From 1874 to 1878 he is listed as a bagpipe and violin maker, as well as his other skills and trades. A violin bearing a paper label (inside the body) that reads "J. Thow Dundee" is pictured to the left.
The bagpipe to the right is believed to be a very early Thow bagpipe.  The original chanter (which matched this set) was stamped "Thow" and is therefore accepted as reliable authentication of the bagpipe itself. 

The bagpipe came to Canada in 1880 from Nairnshire Scotland.  They were the property of James McIntosh who eventually settled in a small village close to Cowansville, Quebec, although at that time is was called Freeport.  James was a blacksmith and distinguished himself making plows. 

This bagpipe appears to have some replacement parts however it is still an excellent exhibit.  The combing is filled with sediment and they have obviously been over-coated. The present owner is the great grandson of James McIntosh.

The top sections contain Thow's signature bead above the cord holders on the bass only and the scribe lines cut into cord holders on all three drones. The projecting mounts are made in a style that resembles the early work of Alexander Glen, ca 1825.
The bagpipe to the left is believed to be equally old. The detail built into the bushing on the bass drone is unique and the bass bushing bore is huge.
The Thow bagpipe above was awarded in 1893 which speaks to the evolution of Thow's bagpipes. Unfortunately we're not able to accurately affix a date to many bagpipes, however by knitting together certain clues we can sometimes get close to knowing when they were made.
The box and papers (below) are from David Thow. The business address is 45 and 47 Gellaty Street, Dundee. David moved the business to that address in 1900. Following his death in 1916, in 1918 the business became Thow Brothers.
More Thow Bagpipes.......
Thow of Dundee