Any member of the police force, fire department, or band in any county not having a civil service commission, who shall be dismissed from service without cause after the member shall have been in actual service for ten years or more, but not exceeding twenty years and who shall be unable through sickness or other disability to support oneself and one’s dependents, shall receive from the pension system a monthly payment equal to twenty-five per cent of the average monthly compensation for the ten years of service immediately preceding the member’s dismissal so long as so disabled.