I've done some British economic history and I don't remember 1830 being given as a key date. The political significance is probably greater, as the relatively liberal Whigs were voted in. This marked an end to the reactionary Toryism that had been prevalent in postwar politics. The 'great' reform act followed a few years later. Economically from this point free trade steadily rose as the dominant ideological. When the Tories next came to power they repealed the Corn Laws.

iwinagain's explanation also seems to make as much sense as any. Really, when it comes to economic history, pinning down a "turning point" to any period shorter than five years tends to seem pretty arbitrary.

It is the Railways. 1830 is the opening of the Liverpool and Manchester railway. This line linked the heart of textile production with a major trading port, there was already a canal but the railroad was faster and cheaper. This railway provided England's first steam locomotive passenger service and had over 400,000 passengers in its first year. The new railroad dramatically lowered the cost of shipping goods and provided the major incentive for other railways to be built.

To an extent the year is simply arbitrary as are many other years used to divide up history. One way to think of it is to consider the voting age as a parallel. Is somebody much more qualified to vote at 18 than they were at 17 years 11 months? Probably not but a line had to be made somewhere. The world didn't dramatically change in 1830 it changed with many small developments over many years but to break history into smaller periods so it could be better understood a line was drawn in 1830 when railways began to change England.

A further question I have is did Britain lose out by being the first industrial country?

On this point I believe being "first" meant development without real competition from Europe or America.. Everyone was importing British textiles because they were so much cheaper, which wouldn't have been the case if say, France, Industrialised first.

A counter argument I've found is that as Britain developed first it made mistakes, obsolete factories as sunk costs and failure to value education highly enough. The failure to educate managers properly lead to poor management and a decline in Entrepreneurial spirit, as other competitors formed in the 1870s crowding out British Industry.

Surprisingly I feel I have a good grasp of why Britain was the first to develop, just not too sure whether being the first was good or bad. Please do correct me if (likely have) anything is wrong.