Very nice old boxed 'COUNTER' by the highly regarded maker LAWRENCE & MAYO. The diameter is 2 1/4" and the depth is 1 1/4" . Not certain of age but would think around 1930 or earlier. Lawrence and Mayo traces its roots to two London based Jewish families, that of Lawrence and Mayo. The two families set up operations all over the world, including London, Cairo, Spain, Portugal, Indian subcontinent, Colombo, Rangoon and Singapore. High-grade Opticians and makers of best quality Survey, Scientific and Meteorological instruments; Lawrence & Mayo has made a rich contribution in India too. It was back in 1877, when Lawrence & Mayo made their foray into India with a showroom in Calcutta. By 1925, Lawrence & Mayo, headquartered in New Oxford Street, London, boasted of showrooms in Alexandria, Bombay, Cairo, Calcutta (Kolkata), Delhi, Lucknow, Madras (Chennai), Rangoon and Simla. By the 117th year of their operations, the company had established its firm presence in 11 cities with 17 showrooms and millions of satisfied customers.