Ross No. 1 brass microscope – circa 1850’s
of the most important microscopes ever designed was the large bar limb
model by Andrew Ross in the middle of the 19th century.
Ross reached a pinnacle of design in both the stand and
objectives that has rarely been equaled, even today.
The microscope is quite large, standing 19” when closed.
It is also quite heavy on a substantial base.
This model is signed, “A. Ross, London, No. 479,” on the
base. Three of the
objectives are original, signed and dated by Ross in 1852.
They feature covered/uncovered correction collar adjustment and
come with their original signed canisters.
These lenses include a 1”, ¼”, and 1/8”.
The fully mechanical stage has a rotating slide holder with
supports for a multitude of accessories.
The condenser is a Gillett illuminator
with its conical ring of minute aperture stops that rotate into place
beneath the condenser lens. It
is signed, “Made by A. Ross, London, Registered July 20th,
1849.” The bottom of the
condenser assembly also accepts a more traditional wheel of stops.
The 3” diameter plano-concave mirror is in excellent condition
on both sides with only the slightest age wear.
An additional seven lenses accompany the set, for a total of ten
-- a 1/5” Smith & Beck correction collar objective, a 3” Edward
Smith, and the rest unmarked objectives that appear to be by Crouch and
Swift. The microscope is
pre-RMS thread standard, and has its own unique lens thread.
All the lenses are threaded to fit the microscope, while the Ross
objectives have an interior thread and fit with an interior thread
adapter that is included with the accessories.
Focus is rack and pinion with a thumb screw micrometer knob for
fine focus. The microscope is finished in lacquered brass
with complete coverage showing typical signs of wear.
The case is hand-dovetailed mahogany with side carry handles in
brass and a brass escutcheon plate on top.
The case is large, measuring 20 ½” tall by 12” wide and 10
¾” deep. It has six
accessory drawers. Two are
for slides – one of these has nineteen slides, some signed by Topping,
Suter, and Murphy. There
are numerous eyepieces including an eyepiece adapter that accepts the
smaller Continental standard size.
Other accessories include two fish plates, condensers (both stage
and standing), several lieberkuhn reflectors, stage forceps, brass
tweezers, different brass slide attachments, nicol prism condenser and
eyepiece, camera lucida eyepiece, and interior thread adapter.
The microscope and case are in excellent condition, noting the
following: one of the adjusting screws on the condenser has stripped
threads, and a number has been hand engraved into the base above the
name (see photo). The
condenser works by hand, nonetheless.
A similar microscope is featured on page 71 of Turner’s book,
This instrument is in fine, working order – extremely rare for
its type and condition. It
is an excellent example of one of the finest and most important
microscopes ever made.