Locations are intended to be accurate to the town/village level, not the street or parish level. They are therefore not placed exactly where an event occurred. Location may also be affected by instances where multiple points are located in the same general area, and have been dispersed to prevent overlap on the map display.
Location-points are more approximate in some cases where (e.g.) only the county constituency of occurrence is known, or an event moves from place to place, such as a violent procession.
Many events will have a constituency listed which does not match its location on the map. This occurs where an event is related to one constituency contest, but takes place within the bounds of another (e.g. when the polling for Hertfordshire, which turns violent, takes place within the borough of Hertford).
Coastal constituencies as displayed on the map often stretch out into the water – this is due to high/low tide and the presence of mudflats.
Constituency boundaries changed substantially throughout the period after the First Reform Act of 1832, until 1910. The two most substantial redrawing of boundaries occurred in 1868 (Second Reform Act), and most noticeably from the 1885 election onwards (After the Third Reform Act).
The constituency boundaries displayed on the map conform to those which applied at the earliest election contained in your filtered search-period. Thus, a search-period of 1832-1914 will display 1832 boundaries, as will a search period 1841-1874. Only a search-period beginning in 1885 will display the boundaries put in place after the Third Reform Act.