Merze Tate, 91, a diplomatic historian and professor who served on the faculty of Howard University from 1942 until retiring in 1977, died of cardiac arrest June 27 at Providence Hospital. She lived in Washington.

Dr. Tate was the author of books on European diplomacy, the history of Hawaii, Great Power rivalries in the Pacific, disarmament and nuclear weapons. Her works included "The United States and Armaments," "The Disarmament Illusion: The Movement for a Limitation of Armaments to 1907," "The United States and the Hawaiian Kingdom" and "Hawaii: Reciprocity or Annexation." In 1973, Howard University published a book of 27 of her research articles called "Diplomacy in the Pacific."

In addition to her writing and work on the Howard faculty, she also lectured and taught abroad. She was a Fulbright lecturer in India in 1950 and 1951 and lectured under the auspices of the U.S. Information Agency in the Indian subcontinent, Thailand, Singapore, Hong Kong, Japan and the Philippines.

Dr. Tate, who was born on a farm in Michigan, was a 1927 honors graduate of what is now Western Michigan University. She received a master's degree in history from Columbia University and a doctorate in political science from Harvard University's Radcliffe College. She also received an economics degree from Oxford University and studied at the Geneva School of International Studies.

From 1927 to 1932, she taught high school history and civics in Indianapolis and in 1935 became a history instructor and dean of women at Barber-Scotia College in North Carolina. In 1936, she became the history and social science department chairman at Bennett College for women, also in North Carolina, where she taught four years. She also spent a year at what is now Morgan State University, where she taught political science and was dean of women, before joining the Howard faculty.

Dr. Tate, a member of Phi Beta Kappa, received at least four honorary degrees. In her later years, she made endowments and funded scholarships at universities where she had studied and taught.

She leaves no immediate survivors. ELIZABETH F. HILBURN Navy Department Supervisor

Elizabeth F. Hilburn, 84, who retired in 1972 as a supervisor of the Naval Regional Accounts office at the Navy Department, died of cancer and emphysema July 5 at her home in Annandale.

Mrs. Hilburn, a native of Frostburg, Md., was a graduate of Frostburg High School. She came to the Washington area in the early 1930s and joined the Navy Department in 1947.

She was a member of St. Michael's Catholic Church in Annandale and a volunteer member of the Fairfax Hospital Women's Auxiliary.

Her husband, Leon L. Hilburn, died in 1973. Survivors include five children, Phyllis Pheimer of Culpeper, Va., Leon L. Hilburn Jr. of Miami, Joseph Hilburn of Woodbridge, Doris A. Menks of Fredericksburg, Va., and Kenneth Hilburn of Stafford, Va.; a sister, Marie Leech of Myrtle Beach, S.C.; a brother, Francis Chabot of Alexandria; 17 grandchildren; and 28 great-grandchildren. ALFRED J.C. GRAHAM Supermarket Manager

Alfred J.C. Graham, 73, who worked as a manager for several Washington area Giant Food supermarkets before his retirement in 1983, died of cancer July 5 at his home in Tazewell, Va.

Mr. Graham worked for Giant Food for 30 years, holding managerial positions at stores in Annandale, Alexandria, Vienna and Washington. He was an Annandale resident during most of his career but retired to Fort Myers, Fla., and later to Morrisville, Pa. He settled in his native Tazewell in 1990.

He was a veteran of the Army Air Forces, participating in the D-Day invasion of France during World War II.

He was a member of Alexandria-Washington Masonic Lodge No. 22 and Kena Temple.

His first wife, Peggy Monk Graham, died in 1982. Survivors include his wife, Betty Watson Graham of Tazewell; and two sisters, Viola Asbury of Tazewell and Dovie Repass of North Tazewell, Va. WILLIAM F. HOBBS Electronics Technician

William F. Hobbs, 86, an electronics technician with C&P Telephone Co. for 40 years before retiring in 1973, died July 5 at his home in Olney after a heart attack.

Mr. Hobbs, who was born in Howard County, was a graduate of both Sherwood High School in Sandy Spring and the old Bliss Electrical School in Takoma Park.

He was a member of Mount Carmel United Methodist Church in Sunshine, Md., and the Alexander Graham Bell chapter of the Telephone Pioneers of America.

Survivors include his wife of 59 years, Margaret G. Hobbs, and a daughter, Margaret Lorraine Joyce, both of Olney; and a grandson.