a. By all rewards, fees, gifts or emoluments paid or given for extraordinary services rendered by any member of the pension corporation, except when the same is allowed by the board of street and water commissioners, or its successors, specifically to such member of the corporation, or when the same is especially given to endow a medal or other competitive reward.

b. By all appropriations, donations, devices and bequests that may be made or given to the pension fund by the city or any person. The city may make appropriation to the pension fund created under this chapter.

c. The city treasurer or other disbursing officer of the city shall retain for the pension fund the amount of four per cent of all salaries and wages due and payable to employees who are or may become members of the corporation. The board of trustees may assess every member of the corporation such further sum as may be fixed by such board in its discretion with the assent of at least two-thirds of the membership of the corporation, which sum so assessed shall be retained by the city treasurer or disbursing officer of the city, from the salaries and wages due and payable to such members. Such assessment shall be made in the manner and form provided in the by-laws of the corporation.

When a member of the corporation dies, leaves or is discharged from the employ of the board of street and water commissioners, or its successor, having served therein for a shorter term than twenty years, all payments, made by the employee to the pension fund shall be forfeited by him and be added to and become part of the pension fund. But if any member, after having paid into the pension fund for a period of over one year, shall resign from the employ of the city, or be transferred from the board of street and water commissioners, or its successor, he shall be entitled to a refund of the sum he has paid into the fund, less the value to him of the insurance benefits he has enjoyed during the period of his membership in such fund, such value being established from time to time by the board of trustees in accordance with current actuarial rates and tables. If any employee is suspended, dropped or discharged from his employment by the board of street and water commissioners or its successor after having paid into the pension fund for a period of over one year, and his suspension or discharge continues for a period longer than two years, he shall be entitled to receive from such pension fund the amount of money which he paid into the fund less deductions for insurance benefits as hereinbefore provided, but such person shall not thereafter be eligible for a pension under this chapter unless upon a re-employment by the city he pays to the pension fund the amount of any rebate made to him. The obligation to refund payments made to the pension corporation shall not apply to any employee suspended or discharged for causes which bar him from eligibility to reappointment under the civil service rules.

d. The city shall raise by taxation and pay into the fund yearly, an amount equal to four per cent of the total salaries paid to such employees.

If there is not sufficient money in the pension fund, the governing body of the city shall include in any tax levy an amount sufficient to meet the requirements of the fund for the time being.

The fund shall be under the control and management of the board of five trustees.