THE LUNG PLAGUE OF CATTLE. 81 



Fans, Moire rx. This valuable provision so easily availed of in any 

 steamer, we only found in practical use on one line (Monarch), sailing 

 from the port of Nc\v York. We understand that some Boston lines 

 are also furnished with blowers. The circular fan, one foot wide by 

 three feet in diameter, and making 180 revolutions per minute, could 

 deliver over 50,000 cubic feet of air per hour. 



Delivered at suitable points and with vent i la t ing outjets properly sit- 

 uated so as to secure a renewal of air throughout the whole space, such 

 an appliance during a storm or a calm like that suggest ed above must 

 be the means of savin- the entire cargo, value, say, sL'f,oon. Indeed we 

 understood that ihe Monarch line is in the habit of insuring the cargo 

 of cattle for a small extra charge, an arrangement which should work 

 to the mutual advantage of steamboat company and exporter, the usual 

 charge off) per cent, being a very large impost on the export. 



We have heard the most serious charges brought against these steam 

 blowers, to the effect that they only caused the whirling and circulation 

 of the bad a/r, but even if this were the case to a partial extent when the 

 point of delivery of the air is badly selected and when there are numer- 

 ous other openings in places ill-adapted to the exit of the impure air, it 

 can furnish no valid objection to ihe introduction of so much pure air, 

 much less when the points of delivery of the pure air and of the escape 

 of the impure are properly arranged at opposite extremities of the space 

 to be ventilated. 



On the whole we would favor the adaptation of the blower so as to 

 extract the impure air rather than to force in pure, and then the open- 

 ings for the entrance of pure air could be made numerous enough and 

 could be sufficiently distributed over the stalls so as to secure to each 

 an abundant supply. These openings for fresh air could be by cowled 

 tubes, booby hatches, or through the hollow masts, and it would be 

 easy to guard them against the introduction of water during storms. It 

 might further be desirable to place boards beneath their internal open- 

 ings to deflect the air and prevent it from forming a continuous draft on 

 certain animals. Screens of wire gauze or peforated zinc would also 

 serve a good purpose by breaking up the current and preventing drafts. 



Extraction of the air by the heat of the furnace. It seems surprising 

 that this simple means of ventilating steamships has not been long ago 

 adopted. So long as there must be a furnace consuming an immense 

 quantity of air in all weathers, there can be no possible excuse for the 

 lack of any needed ventilation in the ship. All that is requisite is to 

 have the means of closing in the ash-box, and connecting it with tubes 

 leading from the different compartments to be ventilated, and then sup- 

 plying these compartments with ventilating inlets placed at the opposite 

 side from the extracting tube, and a constant and unfailing supply of 

 pure air will be kept up. If there is an objection to closing in the ash- 

 box because of the heat, or of the irregularity of the current, the same 

 end can still be attained by carrying metallic ventilating tubes up by 

 the sides of the furnace, or of the boiler, so as to avail of the high tem- 

 perature, and the expansion and rising of gases as the motive force. 



In view of the great dangers attending the shipment of beef cattle on 

 the crowded decks of a steamer, and the suspicion that rests on Ameri- 

 can stock by reason of diseases of the lungs produced in this way, we 

 strongly recommend that each steamer chartered for the cattle trade 

 should be compelled to put in a blower, or to avail of the furnace heat, 

 as suggested, for ventilating purposes, and in either case to provide in 

 appropriate places tubes for the introduction of pure air and the extrac- 

 tion of the impure, and thereby secure satisfactory ventilation. 

 S. Ex. 106 6 



