The sheer numbers involved are mind-boggling: in 1930 Thornbers hit the first of many records the company was to set producing a million chicks a year in its vast hatcheries. By 1937, by which time the company had diversified into ducks, the output was three and a half million birds annually despatched to all corners of Great Britain - later, the world.

A railway magazine noted, in 1946, that every day 2,000 consignments of chicks were leaving Mytholmroyd Station. To put that into context 25 tons of poultry appliances, 120 tons of blankets from Moderna and around 50 tons of textiles and ready-made clothing a month also left by train. To cope, the station - today unmanned - had a staff of 41.

Recalling those heady days from the past when the Calder Valley was at the heart of much more than the traditional textile industry, and Thornbers in particular set the standard in the fiercely-competitive world of poultry breeding, Ann Kilbey enthralled a packed audience of Hebden Bridge Local History Society members, regaling them with a meticulously-researcned story of inspiration, innovation - and sheer, dogged determination.

Given access by the family to Thornbers records stretching back to the early years of the last century, Ann has put together a detailed history of three generations whose endeavours are a remarkable testament to Yorkshire grit and persistence. In the process she talked with family members and many former employees: This is a remarkable tale of an enterprise that started in a very small way but developed into a world leader, at its peak employing nearly 1,500 people; a dynasty which has lasted 100 years," said Ann.

It all began in the most unpromising of circumstances - the strike, in 1906/7 of Hebden Bridge fustian weavers dissatisfied with their wages, which dragged on for two-and-a-half years. Edgar, son of Robert and Lattice Thornber, born at Laneside in 1888 and a mill-worker since the age of 13, was not prepared to sit around waiting for the strike to finish. He had other ideas and decided to turn a popular hobby of the times - poultry keeping - into a business.

"He acquired a few orange boxes, 12 broody hens and some eggs, and set these up in the backyard of the family home at Mayroyd. Soon the number of hens increased to 300; once the enterprise was launched he was never to work in the mill again," Ann declared. "There were times when he was hard pressed to find the money, and his mother dipped into her purse to help, but it is a proud boast of Thornber House that a total of no more than £25 was invested in the company, and everything, apart from modest living expenses, was ploughed back into the business."

In 1911 the family moved to Newhouse Farm where a barn was converted into an incubator room and four acres of land were dotted with dozens of breeding pens.