Helmet Head No.4: Interior-Exterior
1963, cast date unknown
420 x 766 x 423 mm
Inscribed ‘Moore 0/6’ on rear and ‘Moore’ on base
Presented by the artist 1978
Artist’s copy aside from edition of 6 plus 1 artist’s copy
Technique and condition
The outer bronze form was artificially patinated by applying chemical solutions to its surface which reacted with the bronze to produce coloured compounds (fig.6). The variegated green and brown finish would have been achieved using layers of different chemicals. First a chemical such as potassium polysulphide (or ‘liver of sulphur’) was applied, producing a layer of dark brown patina similar in colour to that of its interior surfaces. A more opaque green patina was then stippled onto the outer surfaces. Many different formulas can be used to produce green patinas but they usually contain mixtures of copper and ammonium salts dissolved in water. Green patinas are often relatively soft and fragile and so lend themselves to being rubbed back to reveal the underlying brown on the high points. In the case of this sculpture further depth of colour has been created by stippling a transparent chestnut brown patina over the green layer, possibly using a solution of ferric nitrate. After these layers were applied the surface was given a coating of wax for protection.
How to citeLyndsey Morgan, 'Technique and Condition', March 2013, in Alice Correia, ‘Helmet Head No.4: Interior-Exterior 1963, cast date unknown by Henry Moore OM, CH’, catalogue entry, October 2013, in Henry Moore: Sculptural Process and Public Identity, Tate Research Publication, 2015, https://www
The outer element takes the form of an upright tubular column, extending upwards from the bronze base before curving forwards at a right angle (fig.1). The form swells at this point making it appear top heavy, although it begins to narrow as it projects towards the front where it terminates abruptly in a rounded opening that reveals the interior to be hollow. Another opening has been made directly below it in the thinner, more upright section of the column, although this hole is smaller and more square-shaped (fig.2).
The surface of the exterior form has a slightly mottled and pitted texture, indicating the way in which plaster was applied to the model from which the bronze was cast. Moore has also incised short parallel lines into the outer surface of this form at irregular intervals, particularly at the domed top (fig.4). The exterior element has been artificially patinated and exhibits a range of mottled green hues across its surface.
From plaster to bronze
The vertical element of the interior piece was created by adding plaster to the leg bone of an animal (fig.6). Moore had collected pebbles, rocks and bones since the 1920s, and kept his ever growing ‘library of natural forms’ in his maquette studio, situated on the grounds of his home, Hoglands, in Perry Green, Hertfordshire.2 According to the filmmaker John Read, Moore liked to ‘shut himself away here, rummaging around, pondering and exploring’ the natural shapes of his collection of bones, shells and flint stones.3 Surrounded by these objects, Moore borrowed some of their formal features when it came to designing his own sculptures. In the case of the bone used for this sculpture, Moore added plaster to its base to stabilise it in an upright position, and more plaster to emphasise the rounded protrusion and recession of the socket and to model angular peaks at its apex. Once finished, Moore then made a plaster cast of the object allowing him to smooth and texture the entire surface freely.
After casting, the bronze elements were probably returned to Moore so that he could inspect their quality and make decisions about their surface finish. The reflective surfaces of the interior forms were achieved by applying abrasives and polishing them, and their golden colour is that of the natural bronze. Although the outer surfaces of the exterior form have been cleaned to remove casting residues, there is little evidence to suggest that these surfaces were filed or chased after casting. The exterior piece, however, has been artificially patinated to produce a mottled green colour (fig.8). A patina is the surface colour of a sculpture and is usually achieved by applying chemical solutions to the pre-heated bronze surface. In 1963, the year Helmet Head No.4: Interior-Exterior was made, Moore asserted, ‘I always patinate bronze myself’, explaining that since he alone had conceived the sculpture it was unlikely that anyone else would be able to replicate the exact colour he wanted.5 When it came to assembling the separate elements of the sculpture it is likely that the vertical interior piece was slotted inside a hole at the base of the exterior form before the upper, horizontal section of the interior piece was soldered securely to the domed interior.
Sources and development
The Henry Moore Gift
How to cite
Alice Correia, ‘Helmet Head No.4: Interior-Exterior 1963, cast date unknown by Henry Moore OM, CH’, catalogue entry, October 2013, in Henry Moore: Sculptural Process and Public Identity, Tate Research Publication, 2015, https://www