Welcome to the 27th cache by "Keeper of Time".
The brothers William and Benjamin Trewhella arrived in Australia from Cornwall, England during the gold rush and took up a property at Blue Mount south of Trentham in the Central Highlands of Victoria.
In 1888 they started sawmilling and William who was an engineer set his mind to improving the methods used of clearing bush blocks and the first fruits of his efforts was the original Trewhella Jack. It proved a very useful implement for sawmillers, farmers and others having heavy lifting to do. William went on to design many jacks and stump grubbers as can be seen at WP1.
The timber mill site was cut out by about 1893 and the brothers dissolved their partnership. William moved to Trentham and built the “Sunnyside Foundry” to carry on the manufacture of his jacks, while Benjamin continued as a sawmiller on various sites until 1903, when they joined in partnership again. Benjamin took over a lot of the office work to give William more time for developing new ideas.
The engineering firm Trewhella Bros grew out of the renewed partnership and it was during the ten years from 1893 to 1903 that William developed his hot air engine. The Kyneton Guardian reported on the public trial as follows.
Trewhella's Patent Hot Air Motor Satisfactory Public Trial
There was a large attendance, including a number of ladies, to witness the public trial of the hot air motor, which took place at Mr. W. Trewhella's Sunnyside Iron Works on Saturday afternoon. The leading features of the invention are perfect safety, great saving in fuel, and entire saving of water.
The usual loss of time in getting up steam in other engines is also saved and it is estimated that all the fuel used during the trial, of some three or four hours, would not be sufficient to get up steam in an ordinary steam engine of the same power.
The present motor has been tested up to six h.p., and the amount of fuel consumed is from 3 lb. to 4 lb. per hour.
In larger motors, the amount of fuel required is expected to be less, and from the successful results of the present one, there does not appear to be any limit to the amount of power that may be obtained on the same principle.
The power of the engine is obtained from the expansion of air by heat; the exact and detailed operation of the mechanism for effecting this purpose is not easily conveyed to the lay mind without the aid of diagrams, but the principle is simple in action and easily understood.
In a vertical cylinder, open at the top and fitted with a closed furnace at the bottom, are two pistons; the upper or power piston being packed air tight and traversing about one-third of the upper end of the cylinder performs the functions of transmitting the power developed by the expansive forces of air through suitable mechanism to the crank shaft.
The lower or displacer piston is simply a long, hollow vessel fitting the cylinder loosely, operated by means of a piston rod passing through the power piston and connected with the outer mechanism, and by its motion, draws in a charge of cool air under the power pistons at one portion of the revolution, and later passes the charge through pipes into the furnace.
There it becomes heated by the combustion of the fuel, and following well known laws of gases it expands, and in doing so, forces the piston out in the same manner as steam in an ordinary steam engine. After having done its work, the air is allowed to exhaust through a suitable valve and up the chimney.
Fuel is fed into the furnace by means of a drum revolving air-tight into a semi-cylindrical piston and having a number of pockets in its circumference, each of which picks up a few coals from the hopper, and in revolving drops them in. a passage in the piston into the furnace.
In order to start the engine, a fire is lit in the furnace and allowed to warm up a little, when the lighting door is closed, and a pull at the fly-wheel starts the engine, the whole operation taking but a few minutes. On larger engines, a reservoir of compressed air may be used for starting.
Much time and experiment has been devoted to perfecting the details of the mechanism; also in controlling the heat, for the hot air, like fire, is a bad master which has exhausted the resources of many a scientist and engineer since the beginning of the century and a servant which will, undoubtedly, encroach very largely on the realm of steam before the century closes.
Arrangements have been made to exhibit the motor at the exhibition at Ballarat, and it is to be sent there this week.
Whilst the Trewhella Bros Sunnyside foundry in Trentham has closed down and the site sold, there are still 2 factories (in Ballarat and Birmingham England) that continue to produce many of William’s original jacks. .
WP1 - S37 23.164 E144 19.200
At WP1 you will be at the location of William and Benjamin’s Sunnyside foundry where you will find an artifact and 2 plaques.
Left plaque, what year did the Sunnyside foundry close = ABCD
Right plaque, by what year did electricity drive all the machines = EFGH
Now drive to WP2.
WP2 - S37 23.817 E144 19.152
What year was William Trewhella born = JKLM
Now walk to WP3.
WP3 - S37 23.764 E144 19.171
What year was Benjamin Trewhella born = NPQR
GZ is at S37 23.PMQ E144 19.J(R-E)(D-H)
The cache is a Mint Tin hidden in a typical geocaching manner, I hope you enjoy the tour.
Please ensure that the cache is well hidden before you leave and I would ask that you help maintain the standard of the cache by placing quality swaps only. As always, be mindful of the local wildlife both good and bad.