In the photograph, Hughes' simple receiver is on the left, and his transmitter on the right. Also, contrary to what this article states, Hughes was not born in the United States--he was actually born in London, although his family moved to the U.S. when he was seven.
Popular Science Monthly, August, 1922, page 57:

World's  First  Wireless  Outfit  Found  in  London  Tenement
equipment THE crude but sensitive instruments with which David Hughes first discovered wireless waves have been unearthed in a London, England, tenement and transferred to a place of honor in the South Kensington Museum. Hughes experimented with electric waves long before Marconi, but the latter gained the distinction of being the discoverer because he was the first to recognize them as ether waves.
    The newly found instruments consist of a spring wound device that sent out electric impulses at regular intervals, and a carbon microphone used by Hughes as the detector. History tells us that during an experiment in 1879 Hughes started the transmitter and then walked slowly away from his laboratory with the receiver in his hand, noting how far the sounds could be detected. At times he was able to hear them 500 feet distant.
    Although Hughes was an extremely able scientist, he lived and worked in a frugal manner. Most of his instruments were made up of odds and ends, such as pins, needles, scraps of wire, and pieces of metal utensils. Yet even with these he was able to produce delicate mechanisms that were the forerunners of those in operation today. The carbon grain transmitter was first studied by Hughes and a widely used electrical device known as an induction balance was invented by him. Later he published a theory of magnetism that brought him distinction.
    Hughes was born in America, where he lived during his early years; but after inventing a printing telegraph he moved to England and the Continent. There he tried for many years to have the machine approved by foreign telegraph firms. Finally, after being accepted by the French government, it was adopted by all the leading companies and brought wealth to the inventor.