Linda Collinson of Davidsonville, Md., makes and sells her own moisturizing face cream, which she calls La Crista, at her home. Collinson contends the cream is nonirritating.

Collinson has formed her own company, La Crista Inc., to market her new cream by mail order and has applied for legal protection for her product and its trade name.

Before producing the cream, Collinson had a Baltimore chemist test it for stability and shelf life. She's sold more than 300 of the two-ounce jars, bottled for her by a Virginia cosmetic manufacturer.

Another Maryland inventor, George E. Gould of Rocksville, after nearly three years of research and experimental work, received U.S. Patent No. 4,292,951 on a fireplace and attachments. The invention, according to his first of nine claims, is "a fireplace in a building which substantially prevents smoke from entering the room in which the fireplace is situated."

Gould got the idea for his fireplace after reading a small book by Orton Vrest entitled, "The Forgotten Art of Building a Good Fireplace," which describes the theories of Benjamin Thompson, an American later given the title of Count Rumford by King George III. According to Gould, a fireplace built as called for in his patent will cut the average fuel bill in a home by 50 percent.

The fireplace is metal and can be inserted in any existing fireplace. So far, Gould, a management consultant, has orders for three of them, and he has six other inventions under development. His large-size fireplaces will sell for approximately $1,000 and ones for average homes will sell for $100 to $150.

Patents granted recently to residents of Maryland and Virginia: MARYLAND

Richard J. Yesuratnam of Silver Spring. Fish Landing Net. Patent No. 4,292,753. 5 Claims.

John C. Ebel of Joppa. Center of Gravity-Appraisal Block Game. Patent No. 4,293,128. 2 Claims.

Bohyum Yim of Rockville. Transcavitating propeller. Patent No. 4,293,280. 13 Claims.

Franklin S. Chalmers of Bethesda, et al. Apparatus for Treatment of Hydrocarbon-Containing Mineral Material. Patent No. 4,293,390. 9 Claims.

Martin Jacobson of Silver Spring. Anti-Feedant for Boll Weevils. U.S. Patent No. 4,293,567. 3 Claims.

Erith T. Clayton of Baltimore. Method of Plating With a Portable Mechanical Plater. Patent No. 4,293,584. 2 Claims.

William Pepper Jr. of Bethesda. Touch Panel System and Method. Patent No. 4,293,734. 28 Claims.

Christos A. Kapetanakos of Bethesda. Generation of Intense, High-Energy Ion Pulses by Magnetic Compression of Ion Rings. Patent No. 4,293,794. 13 Claims.

Peter F. Varadi and Ramon Dominguez both of Rockville. Battery Charging Device Employing Solar Cells. Patent No., 4,293,808. 15 Claims.

George E. Sanner of Sparks. Luminaire. Patent No. 4,293,899. 1 Claim.

Constantinos Philippides of Columbia. Clock Invariant Synchronization for Random Binary Sequences. Patent No. 4,293,949. 14 Claims.

James A. Baker of Dunkirk. Tool for Removing Casement Window From Building. Patent No. 4,293,993. 4 Claims.

Albert C. Brooks of Baltimore. Portable Hoist Frame. Patent No. 4,294,176. 10 Claims.

James F. Harkleroad of College Park. Mortar/Concrete Hand-Mixing Tub. Patent No. 4,294,547. 14 Claims.

James H. Coroncos of Friendship. Process for Preparing Beef for Use on a Vertical Rotisserie. Patent No. 4,294,865. 10 Claims.

Gilbert V. Levin of Annapolis and Patricia A. Straat of Baltimore. Device for Conducting Microbiological Radiorespirometric Assays. Patent No. 4,294,931. 8 Claims.

Lester D. Drugmand, of Arnold. Double-Grip Mounting Means for Sheathed Heating Elements. Patent No. 4,295,104. 14 Claims.

Alfred H. Oelzner of Baltimore. Combined Butter Holder Dish and Cover. Design Patent No. 261,214. Term of 14 years.

Roderick F. Bunyea of Cockeysville. Pneumatic Impact Wrench. Design Patent No. 261,222. Term of 14 years.

John C. Linton of Potomac. Fuse Holder. Design Patent No. 261,261. Term of 14 years.

John C. Linton of Potomac. Fuse Holder. Design No. 261,262. Term of 14 years. VIRGINIA

Werner R. Bauer of Richmond. Method of Making Reversing Valve Construction and Parts Therefor. Patent No. 4,292,720. 16 Claims.

George L. Cahen Jr., of Charlottesville. Collapsible Wing Aircraft. Patent No. 4,292,757. 20 Claims.

Reiner G. Brinker of Mechanicsville. Apparatus for Perforating Hollow Cylinders. Patent No. 4,292,872. 2 Claims.

Joseph T. Inglefield Jr. and William L. Mahood of Falls Church. Allergy Testing Apparatus. Patent No. 4,292,979. 13 Claims.

H. S. Muralidhara of Falls Church. Recovery of Active Chitin and Enhanced Protein Metal. Patent No. 4,293,098. 4 Claims.

Leo N. Planakis of Vienna. Game Rackets and Paddles with Nonparallel Playing Survaces. Patent No. 4,293,129. 4 Claims.

Smith A. Rhodes of Chantilly. Method and Apparatus for Encoding/Decoding a Convolutional Code to a Periodic Convolutional Code Block. U.S. Patent No. 4,293,951. 15 Claims.

Arnold Kandel of Fairfax. Truss-Framed Building Structures. Patent No. 4,294,050. 4 Claims.

Charles M. Stancil of Springfield. Projectile Deployed Cable Weapons System. Patent No. 4,294,157. 15 Claim.

Timothy Maloney of Mountain Falls. Thermosiphoning Module for Environmentally Driven Heating and Cooling System. Patent No. 4,294,229. 19 Claims.

Allen J. Kassman of Richmond and Willard A. Geiszler Jr. of Chesterfield. Filter Cigarette With Inlet Vent Zones. Patent No. 4,294,265. 9 Claims.

Lacy A. Rowe of Salem. Sealing Means for Gutter Hanger Fastening Means. Patent No. 4,294,423. 3 Claims.

James K. Shaw of Annandale. Amusement Device. Patent No. 4,294,449. 7 Claims.

Claim: Defines the invention and sets forth the bounds of the property rights granted the inventor.

Copies of any of the above patents can be obtained from the Patent & Trade Mark Office for 50 cents each by addressing orders to the Commissioner of Patents and Trademarks, Washington, D.C. 20231.