Mr. Hannum informed John Dowler that D. McLachlin was looking to build an addition to his saw or grist mill that summer. Dowler then took the liberty of applying to do paid work for McLachlin and asked that a reply to the letter be addressed in the care of Mr. Hannum.
The second grist mill to be built in Arnprior, this stone building was built by Daniel McLachlin around 1850 and it remained in the McLachlin Bros.' posession until 1935. Multiple millers operated the mill and in 1898 the company began to use it as a training headquarters for boy scouts as well as a boarding house. After 1935 it was used for multiple purposes, most notably as Baird's restaurant and coin wash, owned by Bill Baird. In 1975, it was sold to the Ontario Hydro company and unfortunately gutted by fire. Today, one of the original turbines stands as a reminder of its presence, along with a plaque.