Audio‐visual review

1 There is little doubt that one of the most versatile pieces of visual teaching hardware is the overhead projector — and this perhaps is one reason there are so many brands on the market. A recent newcomer is the AV001, from E. J. Arnold & Son. This uses a 650W quartz lamp cooled by a fairly silent 7in fan. The makers claim their equipment has the coolest surface temperature of any similar machine, something they regard as essential for increasing the efficiency of items such as spirit pens, which are liable to dry rapidly in warm conditions. The plate glass top lifts off easily, allowing the Fresnel lens beneath to be ejected from its positioning beneath spring‐loaded clips. This ejection is coupled to a safety cut‐out device. Together with other items in the Arnold range, this projector has been designed to stand up to hard use and, to use their own phrase, as far as possible to be ‘boy proof’.