The Khaki Solar Pith Hat was the British Army designation of this civilian sola topee which was used in a semi-official capacity in India and Burma probably from the late 1890s. It lasted, in army use, at least until the end of the Second World War.
This hat would appear to be a variant of the Cawnpore Tent Club Hat made so popular by the visit of the Prince of Wales, later King Edward VII, to India in 1875/6 and, indeed, it is quite difficult to say which is which from an external view only, although the more expensive Cawnpores were distinguished by their quilted cover. Both hats were made entirely of sola pith – from the flowering plant Aeschynomene asper or other species of the Fabaceae family – and the corruption of sola to solar is easy to understand as all such hats/helmets were so often called “sun helmets.”
The Khaki Solar Pith Hat was used in conjunction with the Foreign Service helmet initially for “fatigue” duties to preserve the more expensive cork Colonial Pattern and later Wolseley Pattern helmets but quite quickly became the “campaign” preferred headdress.
The KSPH was made entirely of sola pith with a drill cotton cover and in addition to the ventilation provided between the headband and shell could have eyelets, two per side, to provide extra airflow. The top ventilator button was often a “dummy” in the sense that no hole penetrated the shell beneath that button.
The Dress Regulations (India) 1931 stated that officers would wear the “pith hats of universal pattern” rather than the Wolseley pattern
(a) When British other ranks are authorized by competent authority to wear pith hats.
(b) Officer instructors and students of the Royal Tank School when on training parades which necessitate work inside a mechanically propelled vehicle.
(c) Officer students at the Equitation School.
(d) British officers of the Indian army may wear the service pattern pith hat, or Cawnpore Tent Club pattern (with quilted cover and no pagri), on all parades and duties, other than ceremonial parades.
The Wolseley helmet was officially replaced by the KSPH by Army Council Instruction (ACI) 284, dated 13th July 1938, for officers although Wolseleys and Cawnpore Tent Club Hats already in possession were allowed to be worn up to the 31st December 1938. ACI 415, of the week ending 28th September 1938, replaced the Wolseley with the KSPH for all ranks serving in Burma.