The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

40 themselves, the ventilation being ef fected by exhausting the vitiated" ait | from the rooms and alleyways, the > fans and ducts being of sufficient ca- pacity for this purpose, the fresh air entering by storm-proof ventilators, doors or other openings in the pas- senger accommodation. This system has the advantage of enabling the heat to be regulated without affecting the ventilation in the staterooms, the tem- perature there being adjusted to suit the varied ideas of the occupants. That ais adjustment is a. matter of. no -small importance will be vouched for by any chief engineer in the Atlantic service; for, should he be so unfortu- nate as to have Americans and Eng- lishmen in staterooms supplied from the same warm air ducts, he will have a condition of things which will give him considerably more worry during the voyage than will the main engines. There are so many manifest objec- tions to placing steam heaters in all the rooms, that it is hardly necessary to enumerate them. They are apt to cause an unpleasant smell when first turned on, the multiplication of valves and pipes is a very serious evil, to say nothing of the risk of some of the heaters freezing and bursting while the vessel is lying in port in winter on the American side. On the other hand, electricity lends itself admirably to individual heating at very small initial expense, as every stateroom is wired for lighting, and it only becomes necessary to increase the size of the wires to provide for the extra current. The only objection to its extended use hitherto has been the cost of operation. With the idea iof meeting the diffi- culties already enumerated, and dis- pensing, if possible, with individual heating, there has been installed on board the Lusitania and the Maure- tania an elaborate system of heating and ventilation which is fully de- scribed and illustrated in the Lusi- tania number of Engineering (Aug. 2, 1907), and the Mauretania number (Woy. & 1907). All this work was carried out by the Thermotank Venti- lating Co., Glasgow, and is, think, without doubt the best and most thor- ough scheme so far supplied to any vessel. One special feature which, in the opinion of the writer, will be found of great advantage in warm weather, is the possibility of being able to reverse the direction of the air currents in the ducts, the fans un- der these conditions exhausting the foul air from the rooms in large quan- tities, thus causing fresh air to be drawn in through open side lights, TAE Marine REVIEW doors, windows, ventilators, and other available openings. ©" 'With regard to the practical work- ing of the system, I believe it has given excellent results as far as the heating and ventilation of the third- class accommodation is concerned, also in the large public rooms and open spaces in the passenger. accommoda- tion. Unfortunately, from structural and other reasons, it has been found impossible to avoid supplying inside and outside staterooms with warm air from the same thermotanks; on that account, I fail to see how it is possible to supply a sufficient quantity of fresh air at the same temperature to ensure proper ventilation to both these classes of rooms, at the same time keeping them at the same temperature. It is only necessary to glance at the plan of the engine and boiler space of these vessels to appreciate the enor- mous amount of heat which must be radiated from surfaces inside the hull. The major portion of this heat, no doubt, escapes 'by means of the fun- nel-hatches, and engine room and stokehold upcast ventilators, but. still a large amount must be conducted through the decks, bulkheads, casings, etc., 'tending to warm up the interior of the vessel. For this reason there must be many inside rooms, even as high up as the promenade deck, which will require but a very small amount of additional heat to make them comfortable, even in the coldest weather, whereas, for the outside rooms on the same deck, with one side, and in some cases two sides, exposed to the weather, a large amount of heat will be required. That this internal heat, so to speak, exists in a vessel, is borne out by observa- tion under all conditions of weather conducted on the steamship St. Paul, which show that unoccupied state- rooms, depending on their position on the vessel, maintained a certain definite temperature above the outside air throughout the voyage. From a careful analysis of the dif- ferent systems of heating, I am led to the conclusion that the one best adapt- ed to large passenger steamers is a combination of a system. similar to that fitted on board the Lusitania and Mauretania, supplemented by a system of individual electrical heating, the whole combination being under auto- matic control. Until very recently there has been no reliable automatic device for regu- lating the temperature of a room warmed by an electric heater. Num- bers of electrical thermostats have been patented, but they have all failed under the test of practical application, and, whatever possible success they may have attained on land, they were -absolutely useless on board a steam- and beams of an exposed deck. ship owing to their extreme sensitive-_ ness to vibration. Some years ago the attention of Dr. Geissenger, surgeon of the steamship St. Paul, was drawn to the necessity of some means of regulating the tem- perature in his stateroom, which was supplied with an electric heater, as he found that if he left the heater on while absent, the room became much too hot in moderate weather, whereas, if turned off, the room became too cold. Any attempt to use existing thermostats was an utter failure, as he at once found that, owing to vibration, the switch controlling the heater would be destroyed in a few hours, and the contact points of the thermostat itself ruined through oxidization. As a final result of his investigations, he has succeeded in constructing an electrical thermostat which is positive in its action, controls the temperature within one degree Fahr., is absolutely unaf- fected by vibration, and requires only ~ 2.75 watts for the controlling current. For use in staterooms, the instru- ment is a combination of two thermo- stats in one case, the one set for a day temperature of, say, 68 degrees Fahr., the other for a night tempera- ture of, say, 64 degrees Fahr., both these temperatures being easily ad- justable to suit the requirements of the occupant of the room, The use of a lower night tempera- ture is very desirable from a _ health point of view, but it has also an im- portant bearing on the quantity of current necessary to maintain this low- er temperature as will be seen later. To change from the one temperature to the other, it is only necessary to throw over an electric switch, when the thermostat takes care of the rest. This thermostat has now been in use in Dr. Geissenger's stateroom for two years with perfect success. That there is a very important sav- ing in the amount of heating current when properly regulated, and that in such case the cost of electrical heating is moderate, is clearly demonstrated by the following report of and deduc- tions from a-<series of observations taken during several voyages of the St. Paul and Oceanic between Nov. aa, 1907, satid: Jan. -25, +1908: The surgeon's cabin is an outside room situated on the first covered deck, and is Z ff, G in. x 8° ft, ame 7 ft. 6 in. high. The ceiling of the room is composed of the bare plating The outside paneling is entirely uncovered between two frames, and, therefore,