FOREST AND STREAM. 
[Jan. 14, 1911. 
the fire alive, and found no odor of gas in the 
engine room. At a suitable distance above the 
bottom to form an ash-pit is located the gate 
and on a line with this are two fire doors for 
slicing the fire and raking off the ashes. An 
ash-pit door is fitted for the removal of ashes 
and clinkers. The coal is fed into the producer 
through a hopper on top and just below, reach¬ 
ing into the center, is the gas take-off pipe. 
1 he side walls of fire-brick are substantially 
vertical and we have then a fire-brick lined 
cylinder filled with anthracite pea coal in va¬ 
rious stages of combustion. While operating, 
the hottest fire zone is from six to eighteen 
inches above the grate. Above this is a red 
hot and black hot layer of coal extending up 
to the take-off pipe. The top of the producer 
is effectively insulated by a considerable layer 
of coal around and above the take-off pipe. 
Thus it will appear that the producer itself is 
extremely simple. 
Contrary to general land practice there is no 
water vaporizer whose function is to generate 
steam vapor which, mixed with the air and 
passed through the fire, serves the double pur¬ 
pose of enriching the gas (the steam forming 
water gas) and softening the clinker. A num- 
ber of attempts have been made to incorporate 
this device with marine producers, but without 
success, owing to the deposit of salt and the 
effect on the vaporizer of the rolling and pitch¬ 
ing of the vessel. It is in fact a mooted question 
whether the presence of considerable water gas 
is not a detriment rather than an assistance to 
a smooth-running engine. This being the case 
it is only necessary to find a substitute for 
steam for the softening of the clinker. Exhaust 
gas introduced under the grate has this effect. 
I he exhaust line from the engine is accordingly 
tapped and a portion of the exhaust by-tapped 
to the producer. To keep the ashes and the 
bottom of the producer cool, a small quantity 
of water is run into the ash-pit, say fifty drops 
per minute on a 75 -horsepower producer. Such 
steam as is formed from this small amount of 
water of course is turned into water gas and 
assists slightly in keeping down the' clinkers 
With proper care the grate should last two 
years or more as the best operating conditions 
require a layer of ashes between the grate and 
the hottest fire zone. The fire-brick lining is 
good for three to five years, according to usage 
and the skill of the operator. Relining is com¬ 
paratively inexpensive. 
The gas is taken off near the top of the pro¬ 
ducer through a two-way water-cooled valve, 
one outlet to the scrubber, and the other to the 
purge stack. The latter carries off the gases 
from the producer when the engine is not draw¬ 
ing same through the scrubber. The purge pipe 
should be of sufficient height to induce enough 
natuial draft to keep the fire alive when stand¬ 
ing by for long periods—weeks if desired. The 
purge pipe is most conveniently run into a 
dummy stack which may also contain the ex¬ 
haust mufflers. The scrubber, whose function 
is to cool and clean the gas, is located on top of 
the engine room house and after the stack on 
the Mary A. Sharp. It is of the static type is 
cylindrical in shape, and fitted with baffles, each 
section being provided with three water sprays, 
d he material is copper and monel metal to 
withstand the effect of salt water from the 
sprays and sulphuric acid from the gas. 
The operation of the producer is exceedingly 
simple and mechanically and chemically similar 
to that of the self-feeding parlor stove. Start- 
tng a new fire, a few bushels of shavings and 
charcoal (preferred) or wood are thrown on 
the grate': As soon as this is lit off the fan is 
started, giving a gentle blast to the fire Di¬ 
rectly coal is fed through the hopper until the 
P r *?d l . lcer is full. Very frequently good gas of 
sufficient volume to operate the engine can be 
obtained in thirty minutes. The coal on the 
grate is burned to complete combustion (COD. 
This gas is reduced to CO on passing through 
the red and black hot fuel zones above. The 
fire can be kept for months at a time and the 
producer is capable of being continuously for 
long periods without shutting down the engine, 
the removal of the ashes and poking down the 
clinker being done while the engine is in full 
operation, and this without any serious fluctu¬ 
ations in the quality of the gas and consequently 
the speed of the engine. The entire system of 
producer, scrubber and piping while the engine 
is operating is under vacuum, the suction of the 
engine inducing a draft in the producer pro¬ 
portional to its speed or power requirements. 
On a plant of the size of the Mary A. Sharp, 
it takes about thirty minutes to clean the fire 
m the morning, that is, poke down the clinkers, 
rake out the ashes, and fill the producer with 
coal. With a small (2-horsepower) auxiliary 
engine for running a blower, it takes about ten 
to fifteen minutes to get up gas, a total of three- 
quarters of an hour from the time the engineer 
steps aboard until he is ready under way. On 
long trips the fire should be sliced on the grate 
and poked from the top every hour. Once an 
hour is often enough to charge with coal. On 
short runs of an hour, or an hour and a half, 
no poking is necessary. 
Perhaps the most interesting feature of these 
two installations is the engine. It is two-cycle 
in principle, in that an explosion is effected in 
each cylinder each revolution, scavenging in 
action and substantially equivalent to the four- 
cycles in efficiency. The commercial use of 
producer gas on shipboard involves the vital 
questions of weight, space, first cost, and sim¬ 
plicity. The two-cycle principle naturally ap¬ 
peals to the imagination of the marine engineer 
as fulfilling these requirements more easily than 
the four-cycle provided it can be made econom¬ 
ical ajtd reliable. In land practice we know of 
the Koerting two-cycle engines which are eco¬ 
nomical on full loads. Now a marine engine is 
operated at full power continuously. Hence it 
is evidently possible to fulfil the specifications 
for economy. Reliability is a matter of careful 
design, good material and workmanship, and 
high grade ignition devices. If the use of a 
four-cycle engine is made difficult by reason of 
its weight, space required and first cost, the 
two-cycle engine should make marine producer 
gas power installations commercial. 
The engines, as stated, are two-cycle. The 
explosive charge after expansion is completely 
blown out by a charge of air before the gas is 
admitted to the cylinder. The admission of the 
latter is so timed that none of the gas is lost 
through the exhaust ports. This gives a clean 
charge of great power and efficiency, and with¬ 
out any possibility of back-firing. Producer gas 
is particularly susceptible to back-firing, due to 
its slow burning, and eliminating all back-fir¬ 
ing in the type of engine described a decided 
forward step has been made. The saving in 
heat losses and in friction due to an explosion 
every revolution in each cylinder compensates 
in large part for the loss in the air gas com¬ 
pressors. The working cylinders are of the 
ordinary construction but with exhaust ports 
extending around the entire circumference of 
the cylinder. The exhaust gases pass with the 
utmost freedom from the cylinders to a large 
water-jacketed exhaust manifold. Differential 
pistons and cylinders are used as gas pumps. 
The downward stroke of the piston induces di¬ 
rect suction on the producer, compressing same 
into a receiver on the upward stroke. This 
receiver communicates with the cylinder heads 
and the air and gas valves controlling their 
admission. Air only is drawn into and com¬ 
pressed in the base and of a volume of about 
50 per cent, in excess of both the working 
piston displacement and the clearance in the 
combustion chamber. Both air and gas are ad¬ 
mitted to the cylinder through mechanically 
operated valves and are so timed that such a 
proportion of the air as is intended for scaveng¬ 
ing is firstly admitted, blowing out the burnt 
gasses. The gas valve is then opened, admit¬ 
ting gas direct to the cylinder and mixing with 
the balance of the air from the base. 
On July 14 and 15 a non-stop run. of eighteen 
hours was made from Baltimore to Sharp’s 
Wharf on the Rappahannock River. Careful 
records were made of distances, revolutions, 
and coal consumed. Following is the condensed 
log of the trip: 
July 14: 
7:48 A. M. Started to blow fire (using hand 
blower) after two nights lay over. 
8:20 A. M. Left dock. 
8:36 A. M. Arrived at coal dock. Took on 
ten tons of coal. 
10:42 A. M. Left coal dock. 
11:30 A. M. Arrived at oil dock. Took on 
one barrel of gasolene for canning factory. 
11:14 A. M. Left oil dock. 
1:55 P. M. Passed Sandy Point. 
6:43 P. M. Passed Cove Point. 
July 15: 
1:33 A. M. Passed Windmill Point. 
5:30 A. M. Arrived at Sharp’s Wharf. 
Cruised around the river. 
6:00 A. M. Tied up and closed draft on 
producer. 
Weather favorable for entire trip with light 
variable winds. Course steered during the night 
not a true one, owing to compass not being ad¬ 
justed. Distance from oil dock to Sharp’s 
Wharf approximately 155 miles, but probably 
covered 160. No stop was made for any cause 
whatever. 
Blowing up fire .. 32m. 
Actual running time . icph. 13m. 
Stand-by . 2h. 25m. 
Average revolutions . 234.5 
Average indicated horsepower. 60.8 
Indicated horsepower hour (allow¬ 
ing 40 per cent, for blowing up 
fire and standbys) . 1,246 
Coal burned (allowing 74 pounds to 
fill producer at end of trip) ... 1,408 lbs. 
Coal per indicated horsepower. 1.13 lbs. 
Weight of engine complete, approxi¬ 
mately . 9,500 lbs. 
Weight of producer. 6,000 lbs. 
Total . 15.500 lbs. 
Weight per B. H. P. (75 B. H. P. 
commercial rating) . 205 lbs. 
Economy of space is important, the 
length of engine and producer 
room being but. 13ft. 3m. 
No particular economy or horsepower tests 
were made on the Superior. She is used as a 
fish-runner out of Bayfield, Wisconsin, collect¬ 
ing fish among the Apostle Islands. This 
service is probably the most severe that a pro¬ 
ducer plant can be subjected to as it is con¬ 
stantly stopping and starting. Some ten to 
fifteen wharves are made in the course of the 
day with stops of from five to thirty minutes. 
Distance Cut by Panama Canal. 
The distance via the Strait of Magellan from 
New Orleans to Callao in Peru is 10,000 miles. 
By the opening of the Panama Canal this will 
be cut to 2,750 miles, according to the Marine 
Journal. From this port to Japan or China via 
the Suez Canal is more than 13,000 miles. By 
the Panama Canal this distance will be 3,000 
miles shorter. From San Francisco to New 
York via the Strait of Magellan the distance is 
13,000 miles. By the Panama Canal 7,790 miles 
of this will be saved, bringing these two ports 
within 5,300 miles of each other. In other 
words, a steamer making 16 miles an hour will 
then reach this port from San Francisco in 
about 14 days instead of 60 as now. 
Where Fresh Water Comes From. 
Of all natural stores of water the ocean is, 
of course, the most abundant, and from it all 
other water may be said to be derived. From 
the surface of the ocean a continuous stream of 
vapor is rising up with the atmosphere, to be 
recondensed in the upper regions and precipi¬ 
tated as rain, snow and sleet. Some eight- 
elevenths of these precipitates return directly 
to the ocean; the rest, falling on land, collects 
into pools, lakes, rivers, or else penetrates the 
earth, perhaps to come to light again in springs 
and wells. 
