Abstract: There is disclosed a calculator adapted to determine optimum fertility time periods for a female, formed by a first scale divided into 365 equal units, each unit assigned a day for each month of a full calendar year, a second scale positioned in operative relation to the first scale, the second scale including a first information segment formed by a series of 15 equal units, each unit representing a day in a menstrual cycle and ranging between 20 such days in a cycle and 35 days in a cycle, and a second information segment positioned a predetermined distance forward of the first information segment, the second information segment comprising the optimum fertility indicator segment and constructed by measuring a time period two days prior to and two days subsequent to the day of ovulation, the optimum fertility indicator segment constructed in the form of a box having a total of eight equal units from end to end, the center unit representing the point of ovulation, and the two markings measured therefrom each b

Abstract: There is disclosed an improved paper clip for retaining two or more pieces of paper together formed by a continuous U-shaped body having an upper wall and a lower wall being spaced apart a distance and joined at one end by a junction portion, the upper wall having a cut-out portion formed therein and having one surface thereof including an inclined surface formed therein, spring means mounted on the upper wall and recessed within the cut-out portion the spring means further including an inclined section formed integrally therewith and positioned in cooperating relation with the inclined surface of the cut-out portion such that the inclined section frictionally engages against the inclined surface, the spring means including paper piercing means formed thereon and extending downwardly therefrom in the direction of the lower wall, the spring means constructed to have an open position when retracted and a closed position when depressed, the lower wall having a receiving slot formed therein and positioned in line