In 1865 he joined the optical company established by his father, Thomas Grubb (1800–78), where he assisted with construction of a 48-inch (1.2-m) reflector for Melbourne, Australia, completed in 1867. Under his control, the company developed a reputation for large telescopes of high quality. In 1914 Grubb moved his business to England where in 1925, as the result of a merger, it became Sir Howard Grubb, Parsons & Company.