The railway sleeping-car is essentially an American institution.  Like every other institution, it has its critics, favourable and severe.  On the one hand, it is said to be the acme of comfort; on the other, the essence of unrest.  But it is just what might be expected under the circumstances, neither one thing nor the other.  No one in his senses would prefer to sleep in a bed which was being bornc violently along over rough and uneven iron when he could select a stationary resting-place.  On the other hand, it is a very great saving of time and expense to travel for some eighty or one hundred consecutive hours, and this can only be effected by means of the sleeping-car.  Take this distance, from New York to St. Paul, as an instance.  It is about 1450 miles, and it can be accomplished in sixty-four hours.  Of course one cannot expect to find oneself as comfortably located as in an hotel; but, all things considered, the balance of advantage is very much on the side of the sleeping-car.  After a night or two one becomes accustomed to the noise and oscillation; the little peculiarities incidental to turning-in in rather a promiscuous manner with ladies old and young, children in arms and out of arms, vanish before the force of habit; the necessity of making an early rush to the lavatory appliances in the morning, and there securing a plentiful supply of water and clean towels, becomes quickly apparent, and altogether the sleeping-car ceases to be a thing of nuisance and is accepted as an accomplished fact.  The interior arrangements of the car are conducted as follows.  A passage runs down the centre from one door to the other; on either side are placed the berths or “sections” for sleeping; during the day-time these form seats, and are occupied by such as care to take them in the ordinary manner of railroad cars.  At night, however, the whole car undergoes a complete transformation.  A negro attendant commences to make down the beds.  This operation is performed by drawing out, after the manner of telescopes, portions of the car heretofore looked upon as immoveable; from various receptacles thus rendered visible he extracts large store of blankets, mattresses, bolsters, pillows, sheets, all which he arranges after the usual method of such articles.  His work is done speedily and without noise or bustle, and in a very short time the interior of the car presents the spectacle of a long, dimly lighted passage, having on either side the striped damask curtains which partly shroud the berths behind them.  Into these berths the passengers soon withdraw themselves, and all goes quietly till morning-unless, indeed, some stray turning bridge has been left turned over one of the numerous creeks that underlie the track, or the loud whistle of “brakes down” is the short prelude to one of the many disasters of American railroad travel.  There are many varieties of the sleeping-car, but the principle and mode of procedure are identical in each.  Some of those constructed by Messrs.