The Madisonian. [volume] (Washington City [i.e. Washington, D.C.]) 1837-1845, 1843-11-13

was severely felt inathe British dock yards and Gen
Bentham, an officer OF engineers, with some OF tn
most eminent niechaoiclans Of tlalperlod, made ma
| marcus experiments % save time, labor and mate
rials, SO profusely expended ia The common mode 0
he,oing, But after expending large sums il expert
menls, they produced nothing more than some neon
Siderable improvements ia the common saw mill By
which they can merely saw straight llnes, even II
crooked timber These Improvements are now used %
a saw mill in the navy yard at Chatham, in England
but as they accomplish more III SAVING than was
obtained before, rather. as they cannot produce
carus in saving zoe should Consider them Of 40 great
value. But what the British mechanicians thus fail
ed TO accomplish, Col. Hamiton has attained u per-
fiction.
Some years ago he accomplished great object ii
mechanics, the Invention Of machine for saving
curved timber for wheels but as all the curves OF
wheel are concentYic this invention, though highly
important in saving time, labor and materials, is aI
inferior, far as mechanical combination and the
magnitude of results are concerned, to his saw for
ship timber Subsequently he enlarged his inven-
tion by applying it to the saving Of chair timber q
species OF work requiring compound clurss, though 10
a degree far less than shipping. With these inven-
tons he went to EuroPe to obtain patents, in which
he succeeded and willie he was in England his at
ant at the navy yard at Chatham to the subject Of
saving curves for ship timber. He examined the
saw mill above mentioned, at Chatham, saw It's de-
fleets, and felt confident Of being able to remove
some time, he supplied that great want machine
for saving timber in every variety Of curve required
with as much accuracy and expedition, and with az
little expenditure Of labor, as has ever been reached
in the saving of straight lines.
We will endeayor 10 describe this machine briefly
yet intelligbly. Let the reader imagine common
saw mill, with log laid upon it, and secured at the
foot, end, remote from the saw, in the usual man
ner. Without any additions, the effect would be the
saving Of straight line, the saw moving perpendi-
cularly, and the log horizontally The first object
is to saw cu1re line instead Of this straight line the
curve bending inlemds from tho two ends to the mid
die, and each of the four sides Of the log re-
tanning its position in relation to the horizon,
tico perpendicular and ttco horizontal. The curve
is marked with chalk the upper surface Of
the logs and the OPERATOR grasping the back Of the
with leuer notch,d at end for the purpose,
guides the edge Of tho saw, by of this lever,
along tho curve, precisely as helmsman would
steer boat with tiller, By this simple continuance
is any required curve produced the cord OF the curve
still remaining horizontal or to speak more plainly,
the horizontal position of the upper surface of the log
still remaining This curve may be drawn upon
centre; from one extremity Of the log to tho other,
or may consist OF any number OF smaller curves,
drawn upon any centres, the saw being guided upon
the chalkcd mark. But at the same time the opera
tor wishes to produce another curve, running proiy
upon the axis Of it. For this purpose, the log turns
upon pivot at each end, the degree Of turning being
regulated BY ScrsU, constructed with a circular
plate fitted TO the lower end of the log. The plate
turns upon its centre and if the Gris Of the log, or
the central point Of its end, be made turn with any
point the surface Of this plate, the log will turn
fast slow, IFS axis is to the centre cir
cumerence of this plate. Then if suppose the
log 10 be ten feet long, and It's axis fixed TO any point
on this plate curve, spiral to It's axis, and OF any
required degree, will be produced. As the log turns
to certain extent with every stroke of the saw, the
curve is perfectly regular through its whole distance
and il the operator wishes TO this curve at
any distance from the upper end Of the log he
verses the motion Of his plate. The degree Of cur
nature be exactly calculated and the axis Of the
log set upon the plate accordingly; and by these two
simple CONTINGENCIES, any required number Of hori
Zonla and Of spiral curves may be produced on sim
gle stick Of timber running once through the saw
mill. Our readers will need no further description
to comprehend tho immense importance Of this in
vention.
But these are not its only merits In plank and
Other timber for ships Of She most important
siderations is strength; and this always impaired
where plank arc curved in straight lines from a log
whose natural Ebres are crooked. Hence 10 produce
plank without dividing the hbrcs or, as il is called,
cuI5g GcToss the grain hanJ3qCing is used, and the
planlls, laid in pile, become straight by pressure
Col. Hamiton's invention which follows accurately
every curve in the fibre orgrdinoi log, with as much
expedition as strengthening can be done, will ei-
lccually abolish tins slow process. But another m-
porlant object is accomplished. In the process Of
herring all the portion cut from the required curve
consists Of chips and therefore is wasted. But the
slabs or portions removed by Col IlamiItons are
curved timber useful FOR shipping other purposes
Several naval architects and especially Foster
Rhodes, Esq Of cur Navy Department, say that this
invention completely supplies those two great wants
in naval architecture the production Of any required
in timber by the rapid process Of mill saving,
and the following, with the saw Of any natural curve
in the flores of log, without that great detriment to
strength grain. cutting Col Hamilton has secured
patent for his invention in every maritime nation in
Europe, and VIC trust that the Federal Government
will be wise enough to adoptit for our Navy.