6g PILEDRIVER 3/4 18th C. -t ^ | 43;) Flg- 67
By Jacob Kley, Rotterdam
Base 450 x 225, overall height 510.
Constructed mainly of mahogany, with brass fittings, this is a model of a three-horse
powered mechanism for driving piles into a river bed to provide a firm foundation for
building. The ram is raised by the horse-powered capstan; when at the top of the
structure it is automatically released. The cycle of rise and fall of the ram is
automatically activated from thé continuous drive provided by the capstan. An air
brake serves to steady the horses when the ram is released.
The inventory describes this object as: “ Een Model van de Engelsche Hei-
molen of het Heiwerktuig van Valoue... door Kley” . According to Desaguliers
(1744, p. 417) this design of piledriver was invented by “ the lat®Mr. Valoue,
Watch-Maker” , and “ it has been and is still in use at the new Bridge at
Westminster” . The construction of this bridge started in 1738, and it was opened in
1750. Bailie, Watchmakers of the World (195.1-.), lists four watch-makers under the name
Vanlove, variously spelt Vanloüé, or Vaulove. The most likely of them to be the
inventor of the piledriver is the first, Matthew or Mathieu, ofSt. Martin’s Lane, London!
who became free of the Clock Makers Company in 1691.
Van Marum attended the auction sale on 20 November, 1788, of the instruments
of the late Mr. Steenstra, and there bought for ƒ 66 : “ De Heimachine van Valoue door
Kley” (MV). A closely similar, but somewhat larger model in the Utrecht University
Museum is said to have been bought in 1756 by the Academy from J. Kley for ƒ 75.
It is probable that Jacob Kley (1716-1791) had ceased working when Van Marum
was buying models.
Desaguliers (1744) 417^ XXVI; Musschenbroek;Ji 7 6 « XI, fig. 1 ^ Utrecht (1968!
M89.
Inv. yl2
70 DRAINAGE MILL 1790 (46)
By Jochem Cats, Amsterdam
Beard, and therefore the signature, is missing.
Base 695 x 390, height to top of cap 520; diameter of sails 940.
The construction is mainly of mahogany, with some boxwood and ebony; very
similar to the mill shown in fig. 68, Cat. ffl^A model of the large, octagonal drainage
mill or polder mill of the South Holland type, with internal scoop wheel. Of the cap
winder. (bovenkruier) variety of mill, this particular construction shows the outside
windeffhuitenkru^) type, familiar in South Holland. The cap is turned from the
ground by the long tail-pole. The tapered body, with curved panels, gives less resistance
to the wind from the descending sail. The water-wheel is fitted closely between walls
so that water is scooped by the paddles from the lower level to the upper. The lift is
conditioned by the radius of the scoop wheel, and in practice the difference in water
level is 1.2-1.5 m. To drain polders deeper than this, ring dykes had to be built and a
series- of windmills constructed.
The Directors’ minute of 21 May, 1790, is for a “ Scheprad-Watermolen” , costing
ƒ 350, and a receipt for this amount was signed by Jochem Cats on 16 July, 1790.
Stokhuyzen | | 96 jQ; 3 3-40.
and 16j i
71 DRAINAGE MILL 1790 (47) Fig. 68
By Jochem Cats, Amsterdam
Signed on the beard: A° I, CAST 1790
Base 640 x 430, height to top of cap 520; diameter of sails 950; bore of Archemedian
screw 60.
This model ofa polder mill closely resembles the mill described above, Cat. 70. Instead
of a scoop wheel, an Archimedean screw is employed, a device first used in drainage
mills in about 1634. With a screw it is possible to pump water from a depth of 4-5 m.,
thus avoiding the necessity of building so many mills. The screw type of water lift is more