A stairway led down to the floor below. Where possible in such manufactories it was usual to separate the heavier tools from the goldsmiths' workbenches. Consequently the stamping press, the large press, the dies, the lathe and the vice bench were all on this floor. Edward Müller, the engineer, worked here operating the presses. Here gold was pressed into form. Dies, female and male, were inserted into the stamping press, with sheet gold between, and the constant swing of the hammer resulted in small gold strikes or stampings to be used as decoration for brooches, lockets, earrings, and so on. Müller also forged tools for use in the manufactory. Henry Hessels was the die sinker and designer. He constructed the steel dies which were stored in shallow cupboards on this floor, and also forged tools such as the mandrels, both large and small. These were tapering round tools used for making such items as studs used to fasten gentlemen's dress shirts, or rings and bracelets for ladies. Undoubtedly the most important aspect of Hessels's work for the firm was his designing of the jewellery to be made. He kept his many pattern books on this floor. Owing to lack of space on the floor above, there were three goldsmiths' benches here, situated on the opposite wall from the die cupboards, again well lit with windows above. August Adamske and Bartholomew Herbstritt, both goldsmiths, worked on this floor. Brinkmann's manager's office, where the lemel box was kept, was also here at the head of the staircase leading to the warehouse below.

The warehouse, where retailers called to inspect brooches, lockets, rings and so forth, and then to place orders to purchase, occupied most of the ground floor. A small enclosed area to the west held the two gas furnaces for the purpose of melting metals.²⁷

Brooch made by Rosenthal, Aronson & Company, c. 1902, pink tourmalines, natural seed pearls, flag, 15, and a fleece. Courtesy CGC Gold Pty Ltd

The Factories and Shops Act was passed in 1885. Regulations pertaining to premises to be used as manufactories of any description were formulated, and inspectors were employed to examine such premises. Plans had to be submitted to the Local Board of Health showing all floors of the building, a cross-section of same, and drawings of the layout of the yard, if any. If living accommodation were provided on-site, details were required. Means of escape in the event of fire had to be provided, as did adequate space for employees. Some method of heating was required as well as suitable ventilation, lighting and sanitary facilities. Safety measures to be taken when using machinery were to be described. Other measures were later introduced under this Act. Unfortunately these plans of the manufactory of Rosenthal, Aronson & Co. appear not to have survived.²⁸

By 1888 as many as 100 hands were employed by the firm, and more than 5000 brooches had been made, in addition to rings, lockets, chains, etc. Having built a prosperous enterprise, David Rosenthal retired in 1889, but still retained a financial interest in the business. Saul Aronson travelled regularly between his London and Melbourne premises, leaving George Aronson in charge of the manufactory in Melbourne. Over time other retail branches were opened in some Australian states.²⁹

The Manufacturing Jewellers' Association of Victoria was formed in 1889, the year Rosenthal retired. Two years later George Aronson and other manufacturing jewellers applied for permission as the Manufacturing Jewellers' Association of Victoria to use carat and guarantee marks. These guarantee marks were a sheaf for 9 carat, a pick & shovel for 12 carat, a fleece for 15 carat and a three-masted ship for 18 carat in respect of goods of precious metals. It is unclear exactly when this marking system began to be used; illustrations of it first appeared in the first issue of the Australian Manufacturing Jewellers', Watchmakers' and Opticians' Gazette in 1906, but agitation for such a marking system had begun before 1885.³⁰

Punch marks used by Rosenthal, Aronson & Co.: a flag with five stars within (facing either left or right); carat marks accompanied by guarantee marks, 9 carat with sheaf, 12 with pick & shovel (not used after 1920), 15 with fleece, and 18 with sailing ship, these being the carat and guarantee marks introduced by the Manufacturing Jewellers' Association of Victoria, possibly first used c. 1880. Courtesy CGC Gold Pty Ltd