A BROADWOOD SQUARE PIANOFORTE IN THE 
AUCKLAND INSTITUTE AND MUSEUM 
ANGELA R. ANNABELL 
AUCKLAND 
Abstract. The constructional details and action mechanism of a nineteenth- 
century square pianoforte from the Museum collection are described, and the date 
of manufacture estimated. Brief reference is made to the New Zealand historic 
background. 
The dismantling for restoration of a pianoforte from the Auckland Institute and 
Museum collection has provided an opportunity to inspect and report on the internal 
action mechanism. The instrument, by John Broadwood and Sons, is of the square 
variety, similar to that previously documented by the writer (Annabell 1983). As in 
that survey, constructional details are summarised here (see Table 1), with special 
attention in this instance to the action mechanism as representative of a specific type 
and stage in the development of pianoforte construction. Also, the present 
circumstances of restoration have made possible the documentation of some details 
and measurements with greater accuracy. Discrepancies in case size from one end of 
the instrument to the other, for instance, are noted, and micrometer measurements of 
string diameters are listed in Table 2. 
THE ACTION (Figs.1,2) 
The internal action mechanism of the instrument is in two sections which may 
each be lifted out in its entirety, the larger section comprising 56 notes, F! to c3, and 
the smaller section comprising 17 treble notes, c*} to f*. Each section incorporates the 
relevant keys with their shafts, escapements, underhammers, and hammers. This 
method of construction facilitates inspection of the mechanism which is essentially 
that of the English Square Pianoforte Action patented by Broadwood in 1815, as 
illustrated by Closson (1974:133). Broadwood’s earlier simple square pianoforte 
action incorporating a double-headed jack activating underdampers and hammers 
was without repetition action (ibid.131). The present instrument has a repetition 
device in which escapement is effected by a “hopper” (short for “grasshopper”), first 
patented by John Geib in 1786 (Harding 1978:56), which has a built-in regulating 
screw (Fig.1). An underhammer lies in reverse direction beneath the hammer proper, 
pushing up the hammer shaft when the mechanism is activated (Fig.l). The two 
removable sections fit back into the pianoforte case in front of the vertical rods of the 
overdampers, which are activated with the mechanism when the key is depressed. 
Rec. Auckland Inst. Mus.25: 57-62 19 December 1988 
