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temperature; therefore, it seems safe to assume that the estimation of elec- tric energy in port is in excess of the sea requirements. The records of actual consumption were obtained by running the heaters of the staterooms from one machine during the entire voyage, and reading the ammeter every two hours. The external temperatures were also taken every two hours. ~ The steamship St. Paul, sailing from both ports three days later than the Oecanic, encountered different temper- atures, and the consumption, as record- ed for comparison, is corrected for these differences, the equation for this vessel being W 20 (R--E--I) for ra- diation, + W220 (R--A) for ventila- tion; where [ = 12 and A == the tem- perature of the incoming air. In presenting these records to the in- stitution, I have divided the consump- tion by the number of rooms occupied on the trip by passengers. It is ob- vious that at no time were all the heaters in use, owing to the wish of some of the occupants for cold air, and that the reduction to an average of one room is rather unfair to a com- "TAE Marine. REVIEW On the charts of the steamship St. Paul (Plate I.) the top lines show the temperatures of the room, ventilating air, and external air. The room tem- peratures are shown for convenience as sharply broken lines, though the change from high to low, and the re- verse, necessarily takes some time. The other temperatures are recorded in curves joining the average for the period, and do not show the hourly variations that are actually found in the ventilating air, when steam is turned on. Combining the known data as to engines, dynamos, and cost of coal with the results of the observations above referred to, we obtain the fol- lowing results: 43 ages per year, during which heat is 'certainly advisable, we get a total of £123 11s per annum, which might be saved by placing the heaters under au- tomatic control, so that, regardless al- together of the luxury of definite tem- peratures, the subject becomes a mat- ter of some financial importance, To apply this system of thermostat control as an adjunct to the thermo- tank system, it only becomes necessary to fit a specially designed electrical ar- rangement for operating the steam supply to the thermotanks supplying air to the staterooms, this arrangement being under the control of a Geissen- ger electro-thermostat adjusted to reg- ulate the temperature in the air ducts so as to maintain a comfortable tem- Source of Power--Compound direct-connected dynamos of about 90 H. P. Per cent. : Lbs. Engine Seficiency in seu chili Gab ecns 85 Coal per lo He Pe iene 3.5 Dynamo, efficiency .....:....5..5..5-. 90° Coal pero Electr; Hs Pes... oie 4.4 Electrical met (€fficieney ...5..2 50.0. .5. 76%2 Coal per «K.-W. 3030.63 ee 5.9 Cost of coal in bunkers, $4.00 (16/5) per ton, 2 c. (1d.) per Ib. Cost of coal per K. W.-hour, say 1.2 c. (2.4 farthings). Taking the cost for coal at 1.2c per perature in the inside rooms. To at- K. W.:, which is certainly. a low ésti- mate, and applying it to the estimated waste of electrical energy, in the case of the Oceanic, we get for the west- SUMMARY OF OBSERVATIONS ON S. S. OCEANIC. Observed consumption of electrical energy in watts............ Calculated 'consumption .......:..... Gee sbeeseietersi Observed consumption on S. S. St. Paul, automatic control cor- rected for- difference in temperature....... Apparent waste on each room, S. S. Oceanic... Waste on voyage of seven days each room in K, W..........- Total waste night and day in K. W........... Number of rooms "occupied: 035.02 .c criss. Total waste on rooms occupied in K. W......... parison of a definitely heated room, however valuable to the engineer, as an average daily record of power used. The records of the Oceanic are espe- cially interesting, in that they show the consumption of energy in two ex- treme conditions. On the west-bound voyage this ship passed through ex- ceptionally cold weather, as evidenced by the average temperature, 37.6 and 35.8 day and night, whereas, on the east-bound passage, the average tem- peratures were 53 and 52.4, tempera- tures more in keeping with the month of May. , In this connection it is surprising to find such a small difference in the con- sumption of power between the two voyages, thus proving the statement already made, that the average passen- ger does not use his heater with rea- son, or even cater for his own comfort in the smallest degree. It will be noted that the corrected consumption of the steamship St. Paul comes into very close agreement with that calculated for the Oceanic, and verifies most strongly the basis on which the latter calculations were made. Voyage West. Voyage East. ay. Night. Day. Night. 872 844 672 644 Ue cat et etree a 555 325 174 | 49 Moe ais. aie ur 536 296 191 0 Bid We dco Oe ne ger 257 467 498 597 27.0 31.9 52.2 34.5 SUE a Sa whines 58.9 86.7 Rie easton e ae 48 50 pee pind < oatee ° 2,827 4,340 bound voyage a loss of $33.92, and east-bound, $52, or on the round voy- age, say, $86, or £17 13s in heating 49 staterooms. For seven round voy- tain this object the temperature of the air leaving the thermotank can be kept constant, or the thermostat so ar- ranged as to maintain a constant dif- ference of temperature between the said air and that outside as may be found most effective. The additional heat for the outside rooms is supplied by individual electrical heaters under the control of thermostats placed in each stateroom. A glance at the graphic record of temperatures on the two trips of the steamship St. Paul at once shows the inability of the engineering staff to properly regulate the temperature of the air as supplied to the vessel, so as Fig. &. " " VOYAGE EAST S S 'OCEANIC' JAN. IS 16 17 18 * 19 20 2i "2@ JAN. 1908 aks ~~ Si; r:-- --"--, pas (020 NS (ON G NuGo N D N OD N= 20 N° N | nt wee! " . ry Lama Pree ed | | w 50 NX ~~ $ Pe : mm E a EXTERNAL iD.53 < 40 Temp |W SRACET saa w a G2 ao FE 1 20° | Has) | \ | 900] . 4 ad - OAY CONSUMATION io NIGHT © 100: | 800 > ; wae : 0.672 4. oe el AVE ace (nay me wee i 700 = Be LA | $s i | oe | ° ee De ear, is S34 ' | z 600 op a 2 pe : eee es cn : | a \ ¢ j bees ee 500 rs 7 a Me | | ke | < 400 $ CALCULATED ki | w OAY CONSUMPTION 2 300 LZ | : a verace {2-174 w A N.49 < 200 Bag aie eis i | 400 -- ei. Dd a CALCULATED PS] Ve oN a. Consum DTION| ° . Ps Goes