A variation on RIA for the detection of Hepatitis A virus is radio-immunofocussing in which viruses in a plaque are reacted with a radiolabelled antibody and an autoradiogram is developed (Rao and Melnick, 1986).

This rangefinder not only measures the distance to the target, but also provides a digital readout of the inches of holdover at that distance.

The only instance I ever remember where this species haunts any building is at the town of Bishop’s Waltham, in this county, where many sand-martins nestle and breed in the scaffold-holes of the back-wall of William of Wykeham’s stables:

The suffix -able changes sing into singable.