USS Shamrock was a large seaworthy steamer with powerful guns, acquired by the Union Navy during the American Civil War. She was used by the Union Navy as a gunboat in support of the Union Navy blockade of Confederate waterways. During the war, she participated in the operation of placing a spar torpedo into the dreaded CSS Albemarle, allowing Shamrock to sail on with the Union fleet to attack and capture Plymouth, North Carolina. After the war, she voyaged to Europe prior to final decommissioning. Shamrock—a double-ended side wheel gunboat built at the New York Navy Yard—was launched on St. Patrick's Day, 17 March 1863. Miss Sallie Bryant, daughter of Mr. William Cullen Bryant. William H. Macomb in command; the next day, Shamrock was ordered to proceed directly to the sounds of North Carolina for duty in that area as part of the North Atlantic Blockading Squadron. At that time, Union naval forces in the sounds were threatened by the Confederate ironclad ram, which in April had sunk Union side wheel steamer, USS Southfield, had enabled Southern forces to recapture Plymouth, North Carolina.

On the 20th, Shamrock reached Hatteras Inlet where orders awaited her to enter Albemarle Sound and take station off the mouth of the Roanoke River to guard against the reappearance of the formidable Rebel ram. For the next four months, Shamrock's operations concentrated on protecting Union shipping from Albemarle, undergoing repairs up the Roanoke River. Late in October, Shamrock served as the mother ship of the steam launch which Lt. William Barker Cushing had brought to the sounds from New York City to attack Albemarle. On the night of 27 and 28 October 1864 Cushing and his team began working their way upriver; the small cutter accompanied them, the crew of which had the task of preventing the Confederate sentries stationed on a schooner anchored to the wreck of USS Southfield. Both boats, slipped past the schooner undetected, Cushing decided to use all 22 men to try to capture Albemarle; as they approached the Confederate docks, their luck turned. They were taken under heavy fire from both the shore and Albemarle.

They closed with Albemarle and discovered that she was defended against approach by booms of floating logs. The logs, had been in the water for many months and were covered with slime, the small craft rode over them without difficulty; when the small civilian craft was against the hull of the warship, Cushing stood up in the bow and detonated the explosive charge. The explosion threw everyone into the water. Cushing stripped off his swam to shore where he hid until daylight; that afternoon, he stole a small skiff and paddled down-river to rejoin the Union forces at the river's mouth. Of the other men in Cushing's boat, one escaped, two drowned, eleven were captured. Cushing's attack blew a hole in Albemarle at the waterline "big enough to drive a wagon in." She sank in eight feet of water. Commander Alexander F. Worley, appointed as her captain about a month earlier, salvaged her guns and shells and used them to defend Plymouth, North Carolina, against subsequent Union attack—futilely, as it transpired.

Albemarle and the launch sank and, for the first time since spring, Union naval forces enjoyed undisputed control of the North Carolina sounds. When the fortunate Gushing made his way back and reported his success, Comdr. Macomb—the senior naval officer in the area—promptly took advantage of his new ascendency and attacked Plymouth, North Carolina. Shamrock, lashed to tug USS Bazely, led a fleet through the winding channels of Middle River on 30 October and the next day engaged the town's batteries and rifle pits from close range. USS Commodore Hull suffered heavy damage in the violent battle which ensued. After the Union bombardment detonated a large magazine, the Confederate defenders evacuated the fortress. Soon a landing party raised the Stripes over Plymouth. Through the ensuing winter, Comdr. Macomb, in Shamrock, directed operations in the sounds, assuring the Union control of these strategic waters as General Ulysses S. Grant relentlessly tightened his grip on Richmond and General William Tecumseh Sherman pushed his army northward from Georgia through the Carolinas.

On 20 March 1865, Macomb reported the raising of Albemarle. Shamrock remained in the sounds directing affairs afloat in the area for several months after the Confederate collapse. In mid-summer, she was decommissioned at the Philadelphia Navy Yard on 15 August. Recommissioned on 17 October 1865, Shamrock next served in the Caribbean and was one of the nine ships comprising the West Indies Squadron, reestablished on 2 December; the following year, the double ender crossed the Atlantic Ocean for service in European waters. She returned to the United States in July 1868 and was decommissioned at the Philadelphia Navy Yard on 10 August. Shamrock was sold on 1 September 1868 to Mr. E. Stannard of Connecticut. United States Navy List of United States Navy ships This article incorporates text from the public domain Dictionary of American Naval Fighting Ships; the entry can be found here

2 Lacertae is a binary star in the constellation of Lacerta. With an apparent magnitude of about 4.5, it is faintly visible to the naked eye. Its parallax, measured by the Hipparcos spacecraft, is 5.88 milliarcseconds, corresponding to a distance of about 550 light years. It is projected against the Lacertae OB1 stellar association to the northeast of the main concentration of stars, but it is to be a foreground object.2 Lacertae is a double-lined spectroscopic binary. Its components are too close to be resolved, however periodic Doppler shifts in its spectrum reveal that there are two stars orbiting each other. Both stars are B-type main-sequence stars, orbiting each other every 2.616 days and with an eccentricity of about 0.04. The primary is estimated to be about one magnitude brighter than the secondary; the primary component is close to moving off the main sequence, has nearly exhausted its core hydrogen. It is estimated to have completed over 90% of its time on the main sequence