Members are arranged in a hemicycle according to their political groups (in the Common Assembly, prior to 1958, members sat alphabetically) who are ordered mainly by left to right, but some smaller groups are placed towards the outer ring of the Parliament. All desks are equipped with microphones, headphones for translation and electronic voting equipment. The leaders of the groups sit on the front benches at the centre, and in the very centre is a podium for guest speakers. The remaining half of the circular chamber is primarily composed of the raised area where the President and staff sit. Further benches are provided between the sides of this area and the MEPs, these are taken up by the Council on the far left and the Commission on the far right. Both the Brussels and Strasbourg hemicycle roughly follow this layout with only minor differences. The hemicycle design is a compromise between the different Parliamentary systems. The British-based system has the different groups directly facing each other while the French-based system is a semicircle (and the traditional German system had all members in rows facing a rostrum for speeches). Although the design is mainly based on a semicircle, the opposite ends of the spectrum do still face each other. With access to the chamber limited, entrance is controlled by ushers who aid MEPs in the chamber (for example in delivering documents). The ushers can also occasionally act as a form of police in enforcing the President, for example in ejecting an MEP who is disrupting the session (although this is rare). The first head of protocol in the Parliament was French, so many of the duties in the Parliament are based on the French model first developed following the French Revolution. The 180 ushers are highly visible in the Parliament, dressed in black tails and wearing a silver chain, and are recruited in the same manner as the European civil service. The President is allocated a personal usher.