Part of the rush and feverish haste was due to the approach of frost, which, as usual in New York, suspended operations in the earth; but the laying of the conductors was resumed promptly in the spring of 1882; and meantime other work had been advanced. During the fall and winter months two more "Jumbo" dynamos were built and sent to London, after which the construction of six for New York was swiftly taken in hand. In the month of May three of these machines, each with a capacity of twelve hundred incandescent lamps, were delivered at Pearl Street and assembled on the second floor. On July 5th--owing to the better opportunity for ceaseless toil given by a public holiday--the construction of the operative part of the station was so far completed that the first of the dynamos was operated under steam; so that three days later the satisfactory experiment was made of throwing its flood of electrical energy into a bank of one thousand lamps on an upper floor. Other tests followed in due course. All was excitement. The field-regulating apparatus and the electrical-pressure indicator--first of its kind--were also tested, and in turn found satisfactory. Another vital test was made at this time--namely, of the strength of the iron structure itself on which the plant was erected. This was done by two structural experts; and not till he got their report as to ample factors of safety was Edison reassured as to this detail. A remark of Edison, familiar to all who have worked with him, when it is reported to him that something new goes all right and is satisfactory from all points of view, is: "Well, boys, now let's find the bugs," and the hunt for the phylloxera begins with fiendish, remorseless zest. Before starting the plant for regular commercial service, he began personally a series of practical experiments and tests to ascertain in advance what difficulties would actually arise in practice, so that he could provide remedies or preventives. He had several cots placed in the adjoining building, and he and a few of his most strenuous assistants worked day and night, leaving the work only for hurried meals and a snatch of sleep. These crucial tests, aiming virtually to break the plant down if possible within predetermined conditions, lasted several weeks, and while most valuable in the information they afforded, did not hinder anything, for meantime customers' premises throughout the district were being wired and supplied with lamps and meters.