REPORT OF NATIONAL MUSEUM, 1921. 105 
tion taken from the hammer-beam roof of Westminster Hall, Lon- 
don, England, during recent repairs to this famous building. The 
roof was built under the orders of Richard IT, in 1399, and the oak 
used therein must be anywhere from 900 to 1,000 years old, or more. 
The roof beams and timbers of this historic structure were found 
to be so weakened by the attacks of larvae of a boring beetle, Yesto- 
bium tessellatum, known as the “ death watch,” that portions of the 
timbers were removed and the roof supported by an invisible steel 
reenforcement. The section of timber presented to the Museum is 
valuable from an historical and entomological standpoint, and in 
addition shows the beauty of the wood itself, the old craftsman’s 
work, and the durability of British oak when used in heavy con- 
struction. The Museum also received for exhibition with the speci- 
men photographs and drawings of Westminster Hall and its roof 
structure, which indicate the spot from which the specimen was 
taken, together with a copy of a report by Sir Frank Baines, upon 
the history and repairs to the roof of Westminster Hall and the 
methods undertaken to combat the ravages of the beetle. 
Specimens and photographs of balsa wood, a material weighing 
but little more than half as much as cork, were presented by the 
American Balsa Co. (Inc.), of New York City. These include a 
cross section of the trunk of a young balsa tree, Ochroma lagopus, 
a squared piece of balsa timber, and an ice-cream container made of 
this recently developed wood to demonstrate its value as a non- 
conductor of heat. The utilization of the wood of this quick-grow- 
ing tropical American tree has been brought into prominence during 
the last few years. The manufacture of buoyancy and insulation 
products, such as life rafts, refrigerators, and parts of lifeboats and 
airplanes, especially in connection with the war with Germany, has 
become very extensive. Eighty thousand floats made of balsa wood 
were used in constructing the 250-mile submarine mine barrage in 
the North Sea. 
The Muskegon Machine Co., Muskegon, Mich., contributed a series 
of 23 specimens representing the work of an industry that goes hand 
in hand with present-day conservation methods. These, the products 
of the Linderman dovetail glue jointer, are small samples of what 
is being done in the way of building up automobile running boards, 
doors, etc., chair seats, moldings, columns, frames, and countless other 
things from small pieces of wood, much of which has been hitherto 
classed as waste and has been conveyed under the boilers to be used 
as fuel. 
A series of specimens showing steps in the manufacture of willow 
baskets was contributed by Mr. Andrew Kessler, of Washington, 
D. C. Mr. Kessler personally made the baskets and parts by hand 
